Bob-omb
Walking, talking bombs. Some of these enemies have wind-up keys and some don't. Their appearance, intellegence, and ally/enemy status differs wildly from game-to-game (for example, in Super Mario Bros. 3 they were mindless explosives, in Paper Mario and Paper Mario 2 they were sentient and civilized).
Notable Bob-Ombs
Paper Mario Stats
HP: 3. Attack: 1, Defense: 0
Tattle: Bob-ombs are pretty temperamental, and they get steaming mad when you attack 'em. You'd better not jump on 'em when they're angry or they'll blow up in your face. In fact, stay away entirely. Attack 'em from a distance with items like Hammers. Or you could send in other things, like shells. If they attack when angry, they'll charge in and explode. So you'd better take care of them before they blow!
Paper Mario 2 Stats
Regular Bob-Omb: HP: 4, Attack: 2, Defense: 1
Bulky Bob-Omb: HP: 6, Attack: 2, Defense: 1
Bob-Ulk: HP: 10, Attack: 4, Defense: 2