Burrow is Chomper's primary special ability in Minion Warfare and Minion Warfare 2: Warmageddon. Chomper dives beneath the ground and begins burrowing at a decent pace (approximately 1.25x his walking speed). Chomper is capable of burrowing for approximately 6 seconds, at which point he will emerge from the ground automatically.
While burrowing, Chomper is completely invincible and can not be affected by any weapons or special abilities (aside from Mac's Stun Pole). Chomper is not undetectable, however; while burrowing, Chomper can be detected by his mohawk, which sticks out of the ground like a shark's fin, and by the sound of him humming to himself.
Using the Chomp attack while underneath an opponent will allow Chomper to erupt from the ground and swallow the opponent whole.
"Burrow beneath the ground like a crazy sandworm and swallow Shockbots from below!"