Born from a sand mound playfully built by a child, this Pokémon embodies the grudges of the departed.
It takes control of anyone who puts a hand in its mouth. And so it adds to the accumulation of its sand-mound body.
It likes the shovel on its head, so Sandygast will get serious and fight any children who come to take it back.
If you build sand mounds when you're playing, destroy them before you go home, or they may get possessed and become Sandygast.