Timebomb of the Ancients

The Delmintalintar's Bomb of the Ancients is an artifact in Heretic. It looks like a floating hourglass. When set, a Timebomb of the Ancients floats where the player was standing for a few seconds, then explodes, causing massive damage (including a large amount of splash damage). It will usually gib a gargoyle with one hit.

Strategy
When the player is being chased by hordes of monsters, it can be effective to leave behind some timebombs to clear them away. The timebomb also acts as a grenade, being very good at clearing rooms with weak monsters. It is overall an extremely effective way to deal significant amounts of damage.