How many pieces does 42666 include?

It contains 321 pieces, 138 of them unique elements, plus 2 minifigures.

What colours make up the tree house?

Tan covers the trunk and platform, bright green and yellowish green build the canopy, with medium azure used as an accent.

Is this set more for display or for play?

The party props and two minifigures point towards active play, though the tree house also stands nicely as a small display piece.

Friends

Cat Birthday Party & Tree House

Set 42666 combines a tree house with a small birthday party thrown for a cat, aimed squarely at animal-loving Friends fans who enjoy a bit of storytelling. At 321 pieces and 2 minifigures, the build stays compact without the scene feeling sparse.

Set number: 42666
Year: 2025
Pieces: 321
Minifigures: 2
Theme: Friends
Different parts: 138

What can I build with it?

View the official building instructions at LEGO® ↗

Parts list 138

As BrickLink list (XML)

Import on BrickLink: Wanted → Upload, upload the file (or paste its content), pick a Wanted List and add the parts.

Spare parts (25)

These extra parts come with the set in case one gets lost.

Minifigures 2

Paisley - Bright Light Yellow Top, Medium Lavender Skirt fig-0157544 pieces × 1
Leo - Red Shirt, Yellow Shorts fig-0162904 pieces × 1

Description

A tree house built to look at

The centrepiece is a tree house with a trunk, branches and a small platform that doubles as a stage for the party. The trunk uses warm tan tones, while bright green and yellowish green leaves give the canopy some real depth. Despite the modest piece count, the structure feels sturdy and reads well from several angles, which makes it work as a small standalone diorama on a shelf. A few extra touches, such as scattered blossom and a small bird's nest tucked among the branches, add further depth to the canopy.

Props that tell the party story

Scattered around the tree house are party touches such as a small cake, bunting and presents, which together with the cat figure spell out exactly what is happening in the scene. These details are small but plentiful enough to give the build a narrative layer rather than leaving it as just a building to look at. Paired with the two minifigures, the party actually plays out rather than being merely implied. Small extras like balloons and a bunting string round out the decoration and can easily be rearranged to suit a different version of the scene.

A nature-led colour scheme

The tan, bright green, medium azure and yellowish green palette leans firmly into its outdoor setting: tan covers the trunk and platform, the two greens build up the canopy, and medium azure adds cooler accents to water or sky details in the decoration. Of the 321 pieces, 138 are unique elements. The full parts list with every colour used is set out on this page, handy for tracking down a specific piece after the build.

How the set plays out

The two minifigures take on host and guest roles for the celebration, with the cat firmly at the centre of the scene. Its manageable size makes it a good pick-up-and-build project, and it slots easily into an existing Friends collection once finished. Owners of other tree house or pet-themed sets can use this one as an extra location within a larger play setup. It also makes a straightforward gift, since the build and its play scene are easy to follow.

FAQ

How many pieces does 42666 include?: It contains 321 pieces, 138 of them unique elements, plus 2 minifigures.
What colours make up the tree house?: Tan covers the trunk and platform, bright green and yellowish green build the canopy, with medium azure used as an accent.
Is this set more for display or for play?: The party props and two minifigures point towards active play, though the tree house also stands nicely as a small display piece.