Octopony (Poniworld Chronicles #7)

Mortimer is an octopony—half octopus, half pony—who laughs at all the wrong times. But he wasn't laughing the day a gang of waterskiing squirrels kidnapped his girlfriend. He's a joker, not a fighter, but it turns out the Nazi ponies have discovered an alien spacecraft buried in ice.
And so Morty ends up having to travel to the Arctic to foil a nefarious plot to unleash an alien supersoldier into Poniworld.
Along the way, he meets a mermaid he helps release from the clutches of a bearded cl...