Blubasaur was birthed from the bowels of an unfortunate typo. Now he is cursed to roam the world through an unholy combination of waddling, rolling and a third action that can only be described as oozing. All the while his desperate, gargled calls of "Blub blub blub" only succeed in warning others of his pending arrival. Doomed to a life of isolation Blubasaur's travels on leaving a trail of drool and flattened brush in his wake.
As for the original, true Bulbasaur... Blubby probably ate him.