The slug was created from a genetic mutation caused by the accidental meltdown of the San Satanos nuclear power plant. After some rods of barium managed to escape out of the back entrance, both the slugs residing under the plant and the stray dogs living next to it gained extreme power (the dogs became the first Nuclear Watchdogs).
- Strengths include creation of mushroom clouds and mini-meltdowns at random. Considered to be highly poisonous and is one of the few monsters heroes and pets aren't stupid enough to eat. Grows when near water sources and can be frequently found in dungeons near the River Stinks.
- Weaknesses include salt, lead, and shoe bottoms.