After a failed experiment in Area 51 this wolf was exposed to copious amounts of radiation and was flung into space. When he woke he was swollen to a bottom heavy form at a gargantuan size out of the middle of nowhere in space where he drifted for 69-70 years until bomber (the bombcario) accidentally ran into his stomach while hurtling away from earth. After a quick talk tinker did what he was doing for the last couple decades and exploded (He can control his explosive power so you really don’t need to worry that he’ll make earth explode) and propelled the two back to earth,where they’ve been best friends ever since...Especially since they both love to swell