Arcpet's few sightings have always been while hovering close to the vicinity of newborn children before disappearing. It's not known what its motivations are, but the children it watched all reportedly grew up having uncannily good luck.
This Pokémon roams about deep in the night seeking such negative emotions as grudges and envy. It is described in mythology as the Pokémon that shaped the universe with its 1,000 arms.