Sandygast is a Pokémon formed from sand. It is mostly a mound of whitish sand dotted with gray pebbles. A tunnel through its center acts as a mouth, and a small depression above that has two pebbles for eyes. A red shovel with a white handle is stuck blade first into the top of its head. On either side of its main body is a smaller mound reminiscent of a stubby arm.
Sandygast is born from grudges that seep into the sand, such as from Pokémon that suffer defeat in battle. It can suck the life force of people or Pokémon through its mouth. Apparently, in the Alola region, sticking a hand into Sandygast's mouth is a way of proving one's courage. A person who grabs Sandygast's shovel or puts a hand in its mouth falls under its control. It uses this power to make children add sand to its body so it can become bigger. A Sandygast that loses its shovel may replace it with something like a branch or a flag, but it is said to keep searching for its lost shovel.