Calvin is one of Zeke's best friends at Woldumar Nature Center. He can be very silly at times but also can be helpful. He sometimes hangs out with Will, and is obsessed with Super Mario Galaxy. He often has a mischievous grin on his face and is always getting in trouble. He has dirty blond hair and in the first game, a black and white striped shirt and jeans. In the second game he wears an orange T-shirt and blue jeans.
Calvin is the fastest of the four WolduWarriors, with Zeke, Steven and Will being all around, funniest and strongest, respectively. Calvin can ambush people and use the attack Zoom. He can also use his Spring Jump to reach high places. His move gotten by training with Mo is Crazy Cool Kick, which does a Tae Kwon Do kick that stuns enemies and sometimes KOs. He is playable starting in Chapter 1-3 in WolduWarriors and Chapter 1-2 in WolduWarriors 2.