From massive worms to sand-dwelling humanoids, many creatures are able to burrow beneath the earth and move within it. These creatures can tunnel underground and reappear elsewhere for devastating surprise attacks against their foes. The distance a creature can burrow in a turn is written immediately after its Burrow ability. A burrowing creature may tunnel on its action, and may erupt from the ground at any point within its burrowing Pace the same round if desired. It cannot be attacked while beneath the earth unless the attacker has some special means of detecting it and penetrating the intervening dirt.

Burrowing creatures strike by erupting from beneath their opponents and taking them by surprise. When this occurs, the Burrowing creature makes an opposed Stealth roll versus the target's Notice. If the creature wins, it gains +2 to attack and damage that round, or +4 if it gets a raise. If the victim wins and was on Hold, he may try to interrupt the burrower's attack as usual.

Savage Worlds Deluxe Edition p. 152