The shoggoth moves up to its speed, and can enter other creatures' spaces if they are Huge or smaller. Each creature whose space the shoggoth moves into must make a Dex save (DC 18); a creature grappled by the shoggoth automatically fails. On a success, the creature is pushed as far as the shoggoth moves, or out of its path to the side. On a failure, the shoggoth engulfs the creature and can keep moving. An engulfed creature can't breathe. It is restrained and moves with the shoggoth. An engulfed creature can escape by using an action to make a Str check (DC 23), moving to a space adjacent to the shoggoth if it succeeds.