Creature

Sand Mimic

CanonOfficial lore from the booksDoTp. 181

The Sand Mimic is a small creature whose true form is shapeless. It can turn itself into an object and back again, though anything it wears or carries does not change with it, and while it stays motionless in object form it cannot be told apart from an ordinary object. When it dies, it returns to its true form.1

Acid does not harm a sand mimic, and its own bite burns like acid. It sees in darkness and has no language.1