Big Bob-omb

Big Bob-omb, later to be renamed as King Bob-omb in future installments, is a boss in Super Mario 64 and ruler of the Bob-ombs. Residing atop the mountain in Bob-omb Battlefield, he is the first boss players will come across, and he appears in the star "BIG BOB OMB ON THE SUMMIT". He must be defeated by picking him up from behind and throwing him onto the ground.

Appearance
Big Bob-omb is a large bipedal Bob-omb with purple arms and legs and yellow extremities. Big Bob-omb has a large crown and white mustache. Similar to the Bob-omb buddies, Big Bob-omb does not have a fuse and only explodes when defeated.

The Big Dud
The Big Dud refers to a minor detail in Super Mario 64 relating to the boss enemy Big Bob-Omb. After Big Bob-omb is defeated, Mario can talk to one of the Bob-omb Buddies in the start of the level who tells him that: "Big Bob-omb is nothing more than a dud now". This is seemingly related to the spheres at the base of the mountain in Bob-omb Battlefield.

There are two Big Steelies at the base of the mountain; however after Big Bob-omb is is defeated one extra Big Steely appears at the base of the mountain. Taking into consideration that Big Bob-omb became a "dud" after his defeat, this implies that the third Big Steely at the base of the mountain is actually Big Bob-omb. Considering that the Big Steelys at the base of the mountain are not launched from a cannon like the other Big Steelys, the two original Big Steelys at the base of the mountain could be earlier generations of Big Bob-omb. This could mean that two earlier generations of Big Bob-ombs were defeated and became "Big Duds".

It is worth noting that Big Bob-omb explodes after he is defeated, so it's possible that the extra Big Steely at the base of the mountain might not be Big Bob-omb's body. However, this might be an intentional simplification since creating a cutscene where Big Bob-omb rolls down the mountain might accidentally draw the player's attention to where he went rather than the star he drops.