Bob-omb is a very minor character featured in IWBTH, seen only in the Bowser boss fight. Towards the end of the fight, Bowser drops a blue Bob-omb, which will hop a few times, and then flash yellow and blue while it walks. If it is shot, it will fly forward, likely hitting Bowser and defeating him in the resulting explosion. If not shot, Bowser will likely either bounce into it himself, or it will most likely just explode as he passes over it. When it explodes, the word "BOMB!" appears in the explosion. It's explosion isn't as big as the Banzai Bill explosion, and it shouldn't hurt you, even if you're in the right corner.