Chansey have pink, egg-shaped bodies. They have hair-like outgrowths on the side of their heads instead of the pigtail they had as a Happiny. Chansey have stubby limbs and have grown a short tail. Chansey's lower body is fully developed and they now have a pouch that holds an egg.

Extremely rare in the wild, Chansey is said to bring friendship and extremely good luck to those who are lucky enough to capture her. Chansey lays several eggs each day. The egg is extremely nutritious and tasty. A kindhearted and charitable Pokémon, Chansey will share her eggs with injured Pokémon she may come across. However, she will not share her egg with anyone who has evil in his or her heart. Chansey walks carefully to protect her egg from damage, but can be startlingly fast when she must run from danger.