Lucky

Chansey is a pink, ovoid Pokémon with stubby arms and dark pink feet. It has tiny eyes and three hair-like growths on each side of its head. The tufts of hair have dark pink tips. On the center of its belly is a dark pink pouch that contains a single white egg. The egg is said to be very nutritious and it lays several new ones every day. Finally, it has a short tail. Chansey is a female-only species with no male counterpart.

A kindhearted Pokémon, Chansey will share its eggs with injured people and Pokémon. However, Chansey will never share its egg to those with evil hearts. The eggs become more delicious if Chansey is raised with love and care. Chansey's egg is used as a high-class cooking ingredient due to the nutrition it has. As a result, Chansey have been referred to as doctors' doubles because of its eggs. Due to its egg being over-harvested, Chansey is extremely rare in the wild and is said to bring good luck and happiness to those who manage to catch it. Fleeing from those seeking its egg has made this once-slow species much quicker on its feet than in the past. It is more commonly found in urban settings. Chansey is the only known Pokémon capable of using the Lucky Punch item. In Pokémon Legends: Arceus, if the player is injured, any nearby Chansey will come to check them out, and then flee when they're fully healed. They don't actually heal the player, however. As mentioned in Sleep Style Dex, Chansey has been observed sleeping while holding its egg carefully. It is believed Chansey is doing this to prevent its egg from cracking. Chansey has four different sleep styles it sleeps in: Sheltered Sleep, Unsheltered Sleep, Overturned Sleep, and Atop-Belly Sleep.

Evolution

Chansey evolves from Happiny and evolves into Blissey.

(Source: Bulbapedia)