Bob-ombs are walking bombs that have feet. There are three types of Bob-ombs:
- There are Bob-ombs with wind-up keys. These are the present-day Bob-ombs. Stomp on one to make it inactive, then throw it at foes before it detonates. Any enemy caught in the explosion is defeated. These Bomb-ombs will never self-destruct on their own. They come from SMB3.
- There are Bob-ombs with arms, which are more common than the SMB3 Bob-ombs. They are aggressive, crudely chasing the player and eventally self-destructing over time. They are dropped from the Albatosses in the sky. Pick one up, then toss it at brick walls or enemies. It will explode shortly after. They come from SMB2.
- Lastly, there are Bob-ombs with no arms or wind-up keys. They are shot from cannons and walk around for a few seconds. They self-destruct themselves sooner than the SMB2 type. A stomp instantly kills them and they are only found in the level Airship Armada.