Purr-fect Party Time!
Celebrate with Churro & Friends

Build a fun-filled tree house with 321 pieces and throw the best cat birthday bash ever! Includes Leo, Paisley, and five adorable feline figures.

🏛 Friends
Set #42666

Cat Birthday Party & Tree House

Cat Birthday Party & Tree House is an adorable playset.

🏆 Best For: Young LEGO builders and cat lovers ⏱ 2 hr build 🧩 321 pcs 🎂 Ages 6+
★★★★☆ 4.0

Fans appreciate the set's cute cat figures and vibrant colors, making it an engaging playset for young children. Some reviewers feel the build is relatively simple and repetitive, but the overall play value is high.

📝 Our Take

Cat Birthday Party & Tree House is an adorable playset. The bright colors, fun accessories, and charming cat figures create an engaging scene for imaginative play, perfect for young LEGO enthusiasts.

This set is perfect for children aged 6+ who love cats and creative role-playing. The build is straightforward and satisfying, offering plenty of opportunities for storytelling with the included minidolls and animal figures. The compact size makes it ideal for smaller play areas.

Skip this if you are looking for a challenging build or complex display piece. Consider larger LEGO Friends sets with more intricate designs and advanced building techniques, such as the LEGO Friends Botanical Garden (41757).

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🧱 Building Experience

🧩
321
Pieces
2h
Build Time
📊
Beginner
Difficulty
📏
18cm × 16cm × 10cm
Dimensions
Build Highlights:
  • Easy-to-follow instructions perfect for young builders
  • Fun and colorful design with lots of play features
  • Includes multiple cat figures and accessories for imaginative play
  • Compact size ideal for smaller play areas

📈 Investment Analysis

↓ Price declining
C+
Investment Grade
⏳ Active
The LEGO Friends theme generally holds moderate investment potential, appealing primarily to collectors of the theme and those interested in specific parts or minifigures. The Cat Birthday Party & Tree House set benefits from its adorable cat figures and play-focused design, which could attract a niche collector base. However, with a falling price trend and relatively high piece count for the price, its appreciation potential may be limited. Its long-term value will likely depend on its availability and the popularity of the included characters and elements.

Not Financial Advice: Content is for educational purposes only. Past performance doesn't guarantee future results. Full disclaimer

📖 About This Set

Discover a paw-some building kit for girls, boys and cat-lovers aged 6 and up. The LEGO® Friends Cat Birthday Party \u0026 Tree House (42666) toy comes with 2 minidolls, 5 cat figures and lots of accessories for imaginative play packed with sweet kitty moments.

This fun toy sets the scene for Churro’s birthday party. 4 of Churro’s feline friends are here too, plus LEGO Friends characters Leo and Paisley. Explore the fun details, including birthday presents, banners and cat-shaped balloons. Kids will love guiding the pets around the cat tree house, where there’s a fish-shaped piñata, a cat toy, cat grass, a water fountain and litter box. Then it’s time for the cats to sit at the rotating table to enjoy Churro’s birthday cake. With so many ways to play with this animal playset, kids can tell a different friendship story every time.

Discover more exciting creative toys (sold separately) in the LEGO Friends universe. This LEGO set comes with the LEGO Builder app for intuitive building.

  • A building kit for cat-loving kids – This LEGO® Friends Cat Birthday Party \u0026 Tree House toy for girls and boys aged 6 and up comes with 2 minidolls and 5 cat figures for imaginative play
  • Cat tree-house toy – Kids can have lots of fun playing with the 5 cats on the cat tree house, which features a fish-shaped piñata with treats inside, a cat toy, cat grass and a water fountain
  • Create stories with the LEGO® Friends characters – This pretend-play set comes with Leo and Paisley minidolls, 5 catfigures, a buildable cat tree house and a buildable birthday cake scene
  • Cat-themed accessories – Kids can create endless fun stories using the accessories, which include a birthday cake with candle, gifts, banners, cat-shaped balloons, a birthdayhat and cat treats
  • A gift for kids who love cats – This animal toy set makes a great creative gift for girls, boys and cat-lovers aged 6 and up or for anyone who would love to build a cat-themed birthday scene
  • Online show – Inspire more creative-play ideas with other sets (sold separately) and the LEGO® Friends: The Next Chapter online show, where kids can get to know the characters of Heartlake City
  • Let’s tell a friendship story – The LEGO® Friends range of building sets lets kids explore different friendship moments, with lots of opportunities to create their own imaginative stories
  • Measurements – 321-piece set with a main model measuring over 7 in. (18 cm) high, 6 in. (16 cm) wide and 4 in. (10 cm) deep

Compare Similar Sets

This set competes with other LEGO Friends playsets in the same price range, offering a focus on animal care and imaginative play. While sets like the LEGO Friends Pet Day-Care Center (41718) provide similar play experiences, this set stands out with its unique birthday party theme and charming cat figures. It's a great choice for those who prioritize adorable animal characters and colorful, engaging designs.

2 Minifigures Included

The set includes two LEGO Friends minidolls, Paisley and Leo, providing familiar faces for fans of the theme. Their outfits are bright and cheerful, fitting the playful theme of the set.

📦 Full Parts Inventory - 108 unique parts • 294 total pieces

Sticker Sheet for Set 42666-1 Sticker Sheet for...
Part #: 10113040 [No Color/Any Color]
Bar Holder with Clip Bar Holder with Clip
Part #: 11090 White
Plate Special 1 x 2 with Clip Horizontal on Side Plate Special 1 x...
Part #: 11476 White
Slope Curved 2 x 1 No Studs [1/2 Bow] Slope Curved 2 x ...
Part #: 11477 Bright Green
Animal, Cat, Sitting with Dark Brown Stripes, White Chest, Ears print Animal, Cat, Sitt...
Part #: 11602pr0010 Medium Brown
Headwear Accessory Bow with Heart, Long Ribbon and Pin Headwear Accessor...
Part #: 11618 Lavender
String with End Studs 11L Overall String with End S...
Part #: 14226c11 Black
Brick Arch 1 x 5 x 4 [Continuous Bow, Raised Underside Cross Supports] Brick Arch 1 x 5 ...
Part #: 14395 Tan
Brick Arch 1 x 6 x 2 - Thin Top without Reinforced Underside [New Version] Brick Arch 1 x 6 ...
Part #: 15254 Medium Azure
Brick Round 2 x 2 Dome Bottom [Open Stud] Brick Round 2 x 2...
Part #: 15395 Bright Pink
Plate Round 1 x 2 Half Circle with Stud (Jumper) Plate Round 1 x 2...
Part #: 1745 Blue
Tile Round 1 x 2 Half Circle Tile Round 1 x 2 ...
Part #: 1748 Medium Azure
Brick Arch 1 x 3 x 2 Inverted [Inside Bow] Brick Arch 1 x 3 ...
Part #: 18653 Medium Azure
Plate Special Round 2 x 2 with Center Stud (Jumper Plate) Plate Special Rou...
Part #: 18674 Dark Pink
Plate Special Round 2 x 2 with Center Stud (Jumper Plate) Plate Special Rou...
Part #: 18674 Blue
Plate Special Round 2 x 2 with Center Stud (Jumper Plate) Plate Special Rou...
Part #: 18674 Bright Green
Plant, Flower with 5 Pointed Petals and Pin Plant, Flower wit...
Part #: 18853 Light Aqua
Brick Special 1 x 2 x 1 2/3 with 4 Studs on 1 Side Brick Special 1 x...
Part #: 22885 Dark Turquoise
Bar Holder with Hole and Bar Handle Bar Holder with H...
Part #: 23443 Reddish Brown
Large Figure Weapon Lightsaber Hilt with Axle Hole and Two Bar Holders Large Figure Weap...
Part #: 24122 Reddish Brown
Headwear Accessory Hat with Small Pin, Clown / Party with Pin Headwear Accessor...
Part #: 24131 Pearl Gold
Plant, Leaves 4 x 3 Plant, Leaves 4 x 3
Part #: 2423 Lime
Tile 1 x 4 with Groove Tile 1 x 4 with G...
Part #: 2431 Bright Green
Plant, Flower, Plate Round 1 x 1 with 5 Petals Plant, Flower, Pl...
Part #: 24866 Bright Green
Plant, Flower, Plate Round 1 x 1 with 5 Petals Plant, Flower, Pl...
Part #: 24866 Bright Light Yellow
Plant, Flower, Plate Round 1 x 1 with 5 Petals Plant, Flower, Pl...
Part #: 24866 Lavender
Brick Round 1 x 1 diameter Tube with 90 Degree Elbow (2 x 2 x 1) and Axle Holes (Crossholes) at each end Brick Round 1 x 1...
Part #: 25214 Tan
Animal, Cat, Chubby with orange Face, Toes, Medium Blue/Lime Eyes print Animal, Cat, Chub...
Part #: 2652pr0003 White
Animal, Cat, Chubby with Bright Green Eyes, Light Bluish Grey Fur print Animal, Cat, Chub...
Part #: 2652pr0007 Dark Bluish Gray
Tile 2 x 3 Tile 2 x 3
Part #: 26603 Blue
Turntable 2 x 2 Female Turntable 2 x 2 F...
Part #: 27448 White
Tile 2 x 2 Curved, Macaroni Tile 2 x 2 Curved...
Part #: 27925 Coral
Container Box 2 x 2 x 1 Reinforced Bottom Container Box 2 x...
Part #: 2821 Bright Light Orange
Container Box 2 x 2 x 1 Reinforced Bottom Container Box 2 x...
Part #: 2821 Bright Pink
Brick Special 1 x 2 with Grille Brick Special 1 x...
Part #: 2877 Tan
Brick 2 x 3 Brick 2 x 3
Part #: 3002 Dark Orange
Brick 1 x 2 Brick 1 x 2
Part #: 3004 Bright Light Orange
Brick 1 x 2 Brick 1 x 2
Part #: 3004 Coral
Brick 1 x 2 Brick 1 x 2
Part #: 3004 Dark Orange
Brick 1 x 1 Brick 1 x 1
Part #: 3005 Coral
Brick 1 x 1 Brick 1 x 1
Part #: 3005 Bright Light Orange
Brick 1 x 1 Brick 1 x 1
Part #: 3005 Medium Azure
Brick 1 x 4 Brick 1 x 4
Part #: 3010 Medium Azure
Plate 2 x 4 Plate 2 x 4
Part #: 3020 Orange
Plate 2 x 4 Plate 2 x 4
Part #: 3020 Medium Lavender
Plate 2 x 3 Plate 2 x 3
Part #: 3021 Light Aqua
Plate 2 x 2 Plate 2 x 2
Part #: 3022 Light Bluish Gray
Plate 1 x 2 Plate 1 x 2
Part #: 3023 Dark Orange
Plate 6 x 10 Plate 6 x 10
Part #: 3033 Lime
Bar 4L (Lightsaber Blade / Wand) Bar 4L (Lightsabe...
Part #: 30374 White
Tile 2 x 2 with Groove Tile 2 x 2 with G...
Part #: 3068b Bright Pink
Tile 2 x 2 with Groove Tile 2 x 2 with G...
Part #: 3068b Bright Light Orange
Tile 1 x 2 with Groove Tile 1 x 2 with G...
Part #: 3069b Dark Turquoise
Tile 1 x 2 with Groove Tile 1 x 2 with G...
Part #: 3069b Medium Azure
Tile 1 x 2 with Cat Food Box, Cat, White 'MEOW BITS' print Tile 1 x 2 with C...
Part #: 3069bpr9932 Light Aqua
Plate Special 1 x 2 with Door Rail Plate Special 1 x...
Part #: 32028 Tan
Technic Axle 2 Notched Technic Axle 2 No...
Part #: 32062 Red
Plant, Plate 1 x 1 Round with 3 Leaves Plant, Plate 1 x ...
Part #: 32607 Bright Green
Plant, Plate 1 x 1 Round with 3 Leaves Plant, Plate 1 x ...
Part #: 32607 25× Yellowish Green
Slope Curved 2 x 2 x 2/3 Inverted Slope Curved 2 x ...
Part #: 32803 Bright Light Blue
Plate Round 1 x 1 with Hollow Stud and Horizontal Bar 1L Plate Round 1 x 1...
Part #: 32828 Black
Slope 33° 3 x 2 Slope 33° 3 x 2
Part #: 3298 Reddish Brown
Headwear Accessory Crown / Tiara Headwear Accessor...
Part #: 33322 Pearl Gold
Bar 1L with Clip [Cut Edges and One Side Hole] [Full Clip] Bar 1L with Clip ...
Part #: 3484 Reddish Brown
Plate Special 4 x 4 with 3 x 3 Quarter Round Cutout Plate Special 4 x...
Part #: 35044 Bright Pink
Plate Special 4 x 4 with 3 x 3 Quarter Round Cutout Plate Special 4 x...
Part #: 35044 Yellow
Plate Special 1 x 2 Rounded with 2 Open Studs Plate Special 1 x...
Part #: 35480 Bright Green
Plate Special 1 x 2 Rounded with 2 Open Studs Plate Special 1 x...
Part #: 35480 Tan
Brick 1 x 3 Brick 1 x 3
Part #: 3622 White
Brick Arch 1 x 4 Brick Arch 1 x 4
Part #: 3659 Bright Light Orange
Technic Brick 1 x 2 [1 Pin Hole] Technic Brick 1 x...
Part #: 3700 Reddish Brown
Plate 1 x 4 Plate 1 x 4
Part #: 3710 Bright Green
Brick Curved 1 x 2 x 1 No Studs Brick Curved 1 x ...
Part #: 37352 Tan
Plant, Stem with 3 Leaves and Bottom Pin Plant, Stem with ...
Part #: 37695 Bright Green
Equipment Candlestick Equipment Candles...
Part #: 37762 Black
Equipment Candlestick Equipment Candles...
Part #: 37762 Reddish Brown
Wave / Flame Small with Pin Wave / Flame Smal...
Part #: 37775 Trans-Orange
Equipment Shovel [Rounded Handle End] Equipment Shovel ...
Part #: 3837 Flat Silver
Antenna 1 x 4 with Flat Top Antenna 1 x 4 wit...
Part #: 3957b Dark Orange
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Plate Round 2 x 2...
Part #: 4032a Medium Azure
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Plate Round 2 x 2...
Part #: 4032a Medium Nougat
Plate Round 2 x 2 with Axle Hole Type 1 (+ Opening) Plate Round 2 x 2...
Part #: 4032a Bright Pink
Brick Special 1 x 1 with Headlight Brick Special 1 x...
Part #: 4070 Bright Light Blue
Plate 8 x 8 with Rounded End Plate 8 x 8 with ...
Part #: 41948 Magenta
Technic Pin 1/2 Technic Pin 1/2
Part #: 4274 Light Bluish Gray
Plate 1 x 10 Plate 1 x 10
Part #: 4477 Medium Azure
Dish 2 x 2 Inverted [Radar] Dish 2 x 2 Invert...
Part #: 4740 Trans-Light Blue
Dish 2 x 2 Inverted [Radar] Dish 2 x 2 Invert...
Part #: 4740 Blue
Brick Special 1 x 1 with Studs on 2 Sides Brick Special 1 x...
Part #: 47905 Blue
Plant, Leaves Stacked 4 x 5 x 1 2/3 Plant, Leaves Sta...
Part #: 5058 Lime
Plant, Leaves Stacked 4 x 5 x 1 2/3 Plant, Leaves Sta...
Part #: 5058 Bright Green
Wedge Plate 2 x 4 Wedge Plate 2 x 4
Part #: 51739 Blue
Plate Round 1 x 1 Swirled Top / Poo Plate Round 1 x 1...
Part #: 53119 Reddish Brown
Animal Body Part, Barb / Claw / Tooth / Talon / Horn, Small Animal Body Part,...
Part #: 53451 Bright Green
Slope 30° 1 x 1 x 2/3 (Cheese Slope) Slope 30° 1 x 1 x...
Part #: 54200 Bright Light Blue
Brick Round 2 x 2 Dome Top with 2 Ears Brick Round 2 x 2...
Part #: 5690 Bright Pink
Technic Axle Connector Hub with 3 Axles at 120° Technic Axle Conn...
Part #: 57585 Light Bluish Gray
Plant, Flower, Peony Rose with 2 Layers Plant, Flower, Pe...
Part #: 5904 Medium Lavender
Technic Axle Connector Smooth [with x Hole + Orientation] Technic Axle Conn...
Part #: 59443 Tan
Cone 1 x 1 [Top Groove] Cone 1 x 1 [Top G...
Part #: 59900 Trans-Light Blue
Cone 1 x 1 [Top Groove] Cone 1 x 1 [Top G...
Part #: 59900 Tan
Plate Round Corner 6 x 6 Plate Round Corne...
Part #: 6003 Lime
Plate Round Corner 6 x 6 Plate Round Corne...
Part #: 6003 Blue
Window 1 x 4 x 3 without Shutter Tabs Window 1 x 4 x 3 ...
Part #: 60594 White
Plate Round 1 x 1 with Solid Stud Plate Round 1 x 1...
Part #: 6141 Trans-Light Blue
Plate Round 1 x 1 with Solid Stud Plate Round 1 x 1...
Part #: 6141 Bright Pink
Brick Arch 1 x 4 x 2 Brick Arch 1 x 4 x 2
Part #: 6182 Coral
Cylinder Half 2 x 4 x 4 Cylinder Half 2 x...
Part #: 6259 Tan
Animal, Fish [Hollow Stud Mouth] Animal, Fish [Hol...
Part #: 64648 Bright Light Blue
Plate Special 2 x 4 with Groove and Two Center Studs (Jumper) Plate Special 2 x...
Part #: 65509 Bright Green
Wool / Yarn Wool / Yarn
Part #: 6900 Bright Light Yellow
Wool / Yarn Wool / Yarn
Part #: 6900 Dark Pink
Headwear Accessory Hat with Small Pin, Cap Headwear Accessor...
Part #: 6913 Lime
Animal, Cat, Kitten Sitting with Open Eyes, White Mouth, Nougat Paws print Animal, Cat, Kitt...
Part #: 69902pr0003 Nougat
Animal, Cat, Kitten Sitting with Yellow Eyes, Dark Pink Tongue print Animal, Cat, Kitt...
Part #: 69902pr0004 Black
Plate Special 2 x 2 x 2/3 with Axle Hole and Grill on Sides (Haybale) Plate Special 2 x...
Part #: 71752 Tan
Hose Rigid 3mm D. 9L / 7.2cm Hose Rigid 3mm D....
Part #: 75c09 Black
Plate Special 1 x 2 with Clip Vertical on End Plate Special 1 x...
Part #: 78256 Reddish Brown
Bar 2L with Stop in Center Bar 2L with Stop ...
Part #: 78258 Tan
Bar 2L with Stop in Center Bar 2L with Stop ...
Part #: 78258 Reddish Brown
Bar 2L with Stop in Center Bar 2L with Stop ...
Part #: 78258 White
Brick Curved 2 x 1 with Inverted Cutout Brick Curved 2 x ...
Part #: 78666 Coral
Brick Curved 2 x 1 with Inverted Cutout Brick Curved 2 x ...
Part #: 78666 Bright Light Orange
Flag 2 x 2 Square, Flared Clip Edge [Thick Clips] Flag 2 x 2 Square...
Part #: 80326 White
Brick Special 1 x 2 with 1 Center Stud on 1 Side, Bottom Stud Holder Brick Special 1 x...
Part #: 86876 Bright Light Blue
Plate 1 x 1 x 2/3 with Open Stud Plate 1 x 1 x 2/3...
Part #: 86996 Dark Orange
Brick Round 4 x 4 Centre Hole Brick Round 4 x 4...
Part #: 87081 Yellow
Panel 1 x 2 x 3 [Side Supports / Hollow Studs] Panel 1 x 2 x 3 [...
Part #: 87544 White
Plate Special 2 x 2 with Groove and Center Stud (Jumper) Plate Special 2 x...
Part #: 87580 Bright Pink
Plate Special 2 x 2 with Groove and Center Stud (Jumper) Plate Special 2 x...
Part #: 87580 Medium Azure
Plate Special 2 x 2 with Groove and Center Stud (Jumper) Plate Special 2 x...
Part #: 87580 Yellow
Bar 5L with Handle (Friction Ram) Bar 5L with Handl...
Part #: 87618 Black
Plate Special 1 x 2 with Bar Up [Horizontal Arm 5mm] Plate Special 1 x...
Part #: 88072 Tan
Plate Special 1 x 2 with Bar Up [Horizontal Arm 5mm] Plate Special 1 x...
Part #: 88072 Green
Cupboard 2 x 3 x 2 with Hollow Studs Cupboard 2 x 3 x ...
Part #: 92410 Blue
Tile Round 1 x 1 Tile Round 1 x 1
Part #: 98138 Trans-Yellow
Tile Round 1 x 1 with Offset Black Eye Print Tile Round 1 x 1 ...
Part #: 98138pr0008 White
Tile Round 1 x 1 with Animal Track Print Tile Round 1 x 1 ...
Part #: 98138pr0056 Medium Nougat
The set includes a good selection of plant elements in yellowish green and lime, useful for adding foliage to MOCs. The tan round bricks and cone pieces are also versatile for various building projects.

🛒 Where to Buy

Target
✓ In Stock
$23.99
LEGO
✓ In Stock
$29.99
eBay
Amazon

💎 Notable Parts

Yellowish Green Plant, Plate 1 x 1 Round with 3 Leaves (25x) $3.75
Lime Plant, Leaves 4 x 3 (8x) $1.60
Reddish Brown Equipment Candlestick (6x) $1.50
Medium Azure Plate Special 2 x 2 with Groove and Center Stud (Jumper) (5x) $0.75
Dark Orange Plate 1 x 2 (5x) $0.50
Est. BrickLink Part Value
$8.10

💡 MOC Potential

🌳 Expand the treehouse into a larger forest scene
🏙 Create a cat cafe with outdoor seating
🏰 Build a small cat-themed castle or kingdom

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📖 Building Instructions 4

Cat Birthday Party & Tree House Instructions
BI 3101, 32, 42666 1/2 V29
Download PDF
Cat Birthday Party & Tree House Instructions
BI 3106, 80+4, 42666 2/2 V29
Download PDF
Cat Birthday Party & Tree House Instructions
BI 3101, 32, 42666 1/2 V39
Download PDF
Cat Birthday Party & Tree House Instructions
BI 3106, 80+4, 42666 2/2 V39
Download PDF

Charts Inventory Statistics

108
Unique Parts
294
Total Pieces
2
Minifigures
Inventory Version: 1