Koopley

"Well, I came here a while back to deal with Hooktail, and all was well and good... But just before my finishing blow, he played a trick on me and gobbled me down whole!"

- Koopley

Koopley is Koops' father in Paper Mario: The Thousand-Year Door. After he came to Hooktail Castle to slay Hooktail, Hooktail swallowed him whole. Koops thought he was dead and joined Mario's team to avenge him. 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.

Trivia

 * As he was in Hooktail's stomach for ten years, he is not very knowledgeable about new technology.