The Gate of the Feral by Matt Dinniman (Dungeon Crawler #4) (Paperback, LARGE PRINT)

New Achievement! Total, Utter Failure.
You failed a quest less than five minutes after you received it. Now that’s talent.

Surviving in a multilevel dungeon that also happens to be the set of the galaxy’s most watched game show has taught Coast Guard vet Carl and his ex-girlfriend’s cat, Princess Donut, that there’s only one thing they can count on apart from each other: they never know what’s coming next. And this floor is no exception.

A floating fortress occupied by warrior gnomes. A castle made of sand. A derelict submarine guarded by malfunctioning machines. A haunted crypt surrounded by lethal traps.

It was supposed to be easy. One bubble. Four castles. Fifteen days. Capture each one, and the stairwell is unlocked. Here’s the thing. It’s never easy. Going it alone is not an option this time, so Carl and his team must rely on the help of the low-level, I-can’t-believe-these-idiots-are-still-alive crawlers trapped in the bubble with them. But can they be trusted?

Welcome, Crawlers. Welcome to the fifth floor of the dungeon.