The Bunny has 5 Hp by default but once Vile Powder is thrown onto the bunny, or if it is a Blood Moon, it becomes Corrupt Bunny and does 30 damage to the player.
The Bunny will hop around during the daytime and stay in place, looking from side to side during the night, like most other non-hostile NPC's. They cannot open or close doors. They cannot be killed by the player, falling stars or explosions, however any hostile NPC can kill them. As well as lava. A corrupt bunny can kill a regular bunny. Vile Powder can affect 2 Bunnies at the same time if they are close enough.
I just got this game. I love it better than minecraft for several reasons.
1.) You start of with a pickaxe
2.) The crafting system is way faster
3.) You can see everything almost everything around you
4.) More mobs/monsters
5.) You start off with a guide
..It's an endless list really. But I seriously enjoy this game.