Koopley

Koopley, a true survivor

Koopley is Koops' father in Paper Mario: The Thousand-Year Door. Ever since he came to Hooktail Castle to slay Hooktail, Hooktail swallowed him whole. Koops thought he was dead and joined Mario's team to avenge his death. After Mario, Goombella and Koops defeat Hooktail, Koopley came out of Hooktail's stomach with the first Crystal Star, the Diamond Star. Koopley survived 10 years in Hooktail's stomach by hiding in his shell.

It turns out that Koopley is actually a really nice father. It's possible that Koops is named after his father.