From the Super Mario Wiki
Koops is a Koopa Troopa from Petalburg, and the second partner to join Mario's party in the game Paper Mario: The Thousand-Year Door. Very much like Kooper from the original Paper Mario, Koops can retreat into his shell and use it as a weapon against foes, and Mario can also launch him at switches or distant objects to hit them or retrieve them. However, he differs from Kooper in that Mario can hold Koops's shell in place. His name is a portmanteau of "Koopa" and "oops", an exclamation of clumsiness (Koops being clumsy).
Paper Mario: The Thousand-Year Door
Koops first meets Mario in Petalburg. He doesn't say much, but before Mario leaves to another part of town, he stops him, then his shyness overcomes him and he goes back. When Mario goes off to Hooktail Castle, he stops him again and is firm that he wants to join Mario's party in order to avenge his 'dead' father, but not before Koopie Koo finds out. She begs him not to go, but he says he has to be a strong Koopa for her. She gets mad, withdraws into her shell, and fires herself at Mario and Koops.
Inside the castle, Koops finds a skeleton that he believes is his father's. Reading the note the corpse was grasping reveals it was actually Kolorado's father. Koops is slightly embarrassed, but then wonders if any of the other skeletons is his father.
When Mario and Koops first meet up with Hooktail, the dragon remarks that they look similar to one that passed by here recently. The battle then starts. Once the fight is finished, a near-dead Hooktail spits up Koopley, who was living in Hooktail's stomach for ten years. After a touching reunion, Koopley reveals he found the Diamond Star in Hooktail's stomach, and allows Mario to take it.
Koops is the only partner with a defense of 1. However, he has the lowest HP of all partners, having 15 HP when at Super Rank.
"That's Koops, from Petalburg. He's got confidence issues... He's a... cringer, y'know? But he's definitely got a serious interest in Hooktail... I wonder why?"
"That's Koops, from Petalburg. He's been waiting here, hoping to join you. He's a bit green, but braver than I thought... I'll have to rethink my first impression. I mean, he seems totally earnest, know what I mean? We should take him along."
Super Paper Mario
In Super Paper Mario, Koops appears as a Catch Card won by winning the Duel of 100 in the Sammer's Kingdom. Koops could also be seen very briefly during the intro, where he and all the other partners from the previous Paper Mario titles could be seen in a photograph at Mario's House.
Attacks and stats
Card Type: Rare
Names in other languages