Battle For The Neverhood
Lolo was immune to the mutation gas, but his sister Lala wasn't. He joins his friends to save everyone from the mutation. Lolo was also the first one to fight the first boss: A giant pterodactyl of Lala at the Extinct Museum.
Lolo is told by Queen Mamuta that the only way to bring his sister to normal is to hit her bobble. Lolo defeats her and reduces her to normal. He continues his adventure until he got to Dr. Kogg's Forteress, where he defeats Kogg and swims home after the entire forteress exploded.