tremorsense

A creature that has tremorsense can see normally regardless of how obscured an area is and regardless of whether creatures or objects are invisible or outside line of effect, but both they and the creature must be in contact with the ground or the same substance, such as water or a web. For instance, tremorsense allows a creature to sense something on the other side of a wall, as long as the creature and the thing are both in contact with the ground or the wall. Tremorsense usually has a radius, beyond which the creature relies on its other senses.

Published in Monster Manual 2, page(s) 219, Monster Manual, page(s) 283, Player's Handbook 3, page(s) 223, Divine Power, page(s) 159, Rules Compendium, page(s) 317.