Burrow is an ability used by the Sand Maggot class of monsters. They dig into the ground where they are immune to damage for a short period of time, after which, emerging once again. Maggots usually Burrow when they are cornered and at low health.
This ability is similar to Fly, only oppositely so.
Damaging Skills
Fire — Fire Arrow • Fireball • Fire Bolt • Fire Hit • Firestorm • Fire Wall • Flame Circle • Hydra • Incineration Nova • Inferno • Meteor
Ice — Arctic Blast • Blizzard • Cold Touch • Fire Hit (Cold) • Freezing Charge • Glacial Spike • Hoarfrost
Poison — Poison Bolt • Poison Breath • Poison Cloud • Poison Spit • Poison Spray • Poison Sting • Poison Strike
Lightning — Lightning • Lightning Arrow • Lightning Globe • Red Lightning Hose • Shocking Hit • Spark Defense
Physical — Blow Dart • Charge • Corpse Cannon • Destructive Strike • Ground Tentacle • Leap • Leech-life Ball • Quill Dart • Slam
Magic — Bone Spirit • Hellish Projectile • Unholy Bolt
Non-damaging Skills
Indirect Attack — Blood Mana • Curses • Mana Rift • Minion Frenzy • Putrify • Spin Web • Stun
Spawning — Bone Prison • Festering Appendages • Lay Egg • Revive • Summon Minion
Self-effect — Bone Armor • Burrow • Fly • Frenzy • Heal • Teleport • Vile Effigy