Dig Maneuver

It takes extra effort to dig vertically through the ground as opposed to tunneling horizontally, requiring a creature to use a special maneuver. To use the Dig maneuver, a creature must have "burrow" in their speed entry, they must have a speed that is equal to or greater than their size, and they must be touching terrain that can be burrowed through.

When a creature uses the Dig maneuver, they can move vertically up to a number of squares equal to their size. If a burrowing creature has a creature who is not unconscious grabbed, they can't willingly move deeper into the ground. It's too difficult to dig with a flailing enemy in your claws.