Bob-omb

Bob-ombs are enemies that appear in SM64 and SM64DS, they have a counterpart that can open cannons for you in levels called the Bob-omb Buddy.

Behavior
When spotting Mario they will run up to him and follow him around before exploding. Mario can pick up the Bomb-omb and throw it to make it explode.

Bob-omb clipping
Probably one of the more useful glitches seen in speedrunning SM64 is Bomb Clipping. It is where a player must throw a bomb omb and throw it and then pick it up right before it explodes. This is usually used to clip behind the star behind the Chain Chomp in Bob-omb Battlefield.

However, the glitch is not present within all copies as a result of The Self-Patching Anomaly.

Bom-omb
It's unclear why, but some players remember Bob-ombs as a Bom-omb. It might be a case of the Personalization A.I. changing the dialogues or signs in the game, or it might just be misremembering.