Kirby’s hamster friend from Kirby’s Dream Land 2 is Rick. He is one of the game’s three animal friends and helps Kirby move through difficult terrain.
Rick debuted in Kirby’s Dream Land 2, released for the Game Boy in 1995. Kirby can ride Rick during the adventure, and the hamster’s abilities make him especially useful on icy surfaces: Rick runs faster than Kirby and does not slip on ice. Riding him also changes how some of Kirby’s powers work, creating combinations that differ from Kirby’s normal attacks.
Rick is part of a trio of animal companions introduced in the game. Coo is an owl who can fly through strong winds while allowing Kirby to inhale in midair, while Kine is an ocean sunfish who excels underwater and lets Kirby inhale beneath the surface. These characters are therefore easy to confuse, especially because all three are introduced together.
Rick continued to appear in later Kirby games and spin-offs, sometimes alongside Coo and Kine. His name is also occasionally associated with the broader Animal Friends group, but the specific hamster in this question is unambiguously Rick.