New Structure in the Clouds with new Mob Fluffy

I want a new Minecraft structure, including a new mob. Rarely (very rarely) you might spot a strange cloud in the sky that doesn’t seem to be moving. If you look up, you’ll see a small house on the cloud, with a garden and a pond. Inside the house is a new mob: the Fluffy. The structure should be built solely from existing blocks, for example white glass or wool, and wood from the Dappled Forest. The Fluffy should have the following characteristics:

- It should explode like a Creeper but cause no damage; instead, it should simply knock all mobs back. Afterwards, it is briefly immobilised.

- It should also knock enemies aside, briefly slowing them down.

- You can tame it by feeding it wool. Afterwards, it will follow you and help you with the abilities mentioned above.

- If it touches water, it sinks to the bottom and dies unless you feed it a sponge within 2 minutes to dry it out, after which you’ll receive a wet sponge.