Bubberu was a monster that died.

Unlike other monsters sent to G-Urth from the Bastion of Final Hell, Bubberu had a shard of goodness in his heart. He did not attack the first human he met, an initially horrified woman, and instead pranced about like an animal, eager for attention and praise. Soon, the woman had taken a liking to Bubberu, despite the latter's resemblance to a humanoid made of rocky feces, and a bond between the two was born.

When the Dark Slam Gods found out that Bubberu was acting against orders, Damndeeder and a few other monsters descended to retrieve Bubberu. Bubberu was then put in the Mega Chamber, making him a hundred times larger, and re-released onto the world. The Mega Chamber also had the effect of increasing Bubberu's Rage Gauge; effectively, he became chaos itself.

Bubberu hadn't much time to act out his new feelings before a Giant Robot arrived and blew him up using its ultimate attack, TITAN NOVA.