Rabbits

Carrots, golden carrots, and dandelions can be used to breed rabbits. Earlier in the game, they could also be tamed.

Leads work on rabbits.

Wolves, foxes, and stray cats will hunt rabbits.

The Killer Bunny can currently only be spawned by using commands; it used to spawn naturally much earlier in the game. When attacked by a wolf or fox, it will fight back, unlike its more docile counterparts.

Using a name tag to name a rabbit Toast will give it a unique black-and-white texture. Renaming the Killer Bunny to Toast will also change its skin, but it will retain its hostility.

Rabbits will not destroy carrot crops, but they will “eat” fully-grown carrot crops until the carrots revert to their freshly planted form.

When within eight blocks of a player, rabbits will run away. They also run away when they are within four blocks of most hostile mobs; a few exceptions include slimes, magma cubes, skeleton horses, and zombie horses.

Rabbit fur patterns typically coincide with the biomes in which they spawn, unless they spawn as the result of manual breeding (in this case, they will often have the same pattern as one of the parent rabbits).

Pocket Edition featured an exclusive rabbit variety not found on the other platforms.

The original rabbit was much larger and had more health points than the current rabbit

Notch originally intended for rabbits to act similarly to creepers, but his idea was too graphic for the game.

Bonus Fact

Rana, Black Steve, Steve, and Beast Boy were test mobs exclusive to the Indev version of the game.

Citations:

iDeactiveMC. “20 Things You Didn’t Know About the Rabbit in Minecraft.” YouTube, YouTube, 12 May 2018, https://www.youtube.com/watch?v=aYV2k9RqI70. 

Roberts, Zachary. “Top 5 Removed Mobs That Should Return to Minecraft.” Sportskeeda, Sportskeeda, 23 Feb. 2022, https://www.sportskeeda.com/amp/minecraft/top-5-removed-mobs-return-minecraft.

Personal experience (and experiments!)