Mutated dog hated Junkyard all his life and secretly wished to get away. Let's face it, it's a dump, and the low-brow mutants he usually hangs around with has been chipping away at his sanity for years, constantly drunk on mushroom brew, fighting and making crude jokes. Finally he managed to reach Core City. It's so big and full of opportunities! And there are Muties there who are cool, hang out in sewers and discuss art, philosophy and politics. He has never before truly felt at home.
Then one day one of his Mutant "friends" from Junkyard shows up and acts like a complete jackass. Mutated Dog is embarassed. He doesn't want his cool new Mutie friends to know what sort of people(?) he used to hang out with. Mutant accuses Mutated Dog of having become stuck-up city slicker who has forgotten his roots, and decides that the only correct course of action is to abduct Mutated Dog and bring him back to Junkyard.
This freaks Mutated Dog out completely. He never wants to go back to that backwater hellhole! Out of sheer terror of being stuck once again in the worst environment of Lower Underrail he attacks Mutant, killing him.
So there you have it.
