Werewolves are creatures that are found on two worlds in Videoland: Castlevania and Excalibur. They are loosely based on the enemy of the same name from Castlevania II: Simon's Quest and Wizards & Warriors.
Android Mike Vincent summoned a Werewolf along with Frankenstein, a Mummy, and the Count to attack Kevin Keene. While the rest of the N Team handled the other monsters, Kid Icarus defeated the Werewolf by shooting it with a Bon Voyage Party Arrow, which carried it away with balloons.
Android Mike Vincent was later ambushed by a Werewolf during his race against Kevin, but he destroyed it with a single Zapper shot. Whether this was the same Werewolf he summoned earlier or a different one is never established.
When the N Team traveled to Excalibur to find a way to wake Princess Lana from her magical slumber, Simon used his whip to take to the trees and outpace Kevin and Duke. While imagining what he would do when he found the sleeping Lana, he accidentally hugged and kissed a Werewolf that dropped in on him, which Kevin then blasted with his Zapper.
When the N Team was in the Mirror Warp, a dark furred Werewolf was shown acting affectionately to the N Team, further showing how everything is opposite there.