Isaac's tears become guided missiles, controlled in the same way as those fired by the Doctor's Remote item. When fired, a large crosshair appears on the ground in front of Isaac which can be moved by either arrow keys or by clicking with the mouse. After approximately one second a missile will drop from above onto the crosshair, exploding with the same range as a normal bomb and dealing a large amount of damage.
The damage and fire rate of the missiles, as well as the travel speed of the target crosshair, are fixed and are completely unaffected by any other items or stat changes.
Locks firing rate (including that of multi-shot effects like Mom's Eye) to the time it takes for the missile to strike and detonate.
Use the mouse for convenience.
- Epic Fetus overrides almost all tear-changing items.
- Mom's Bra - If used while the missile is in air, it freezes and won't fall.
- Bob's Curse - Makes the explosion green when the missile lands, but the poison effect doesn't work
- Chocolate Milk - Shooting once triggers a missile where Isaac is standing, but doesn't allow control of it. Shooting a second time allows control.
- Brimstone, Dr. Fetus, IPECAC, Mom's Knife - These items are completely overridden by Epic Fetus and have no effect. If you already have Mom's Knife, Epic Fetus will do nothing until the room is left, and if you already have Brimstone, Epic Fetus missle will drop wherever you are standing when you fire a beam until that room is left.
- The Common Cold, Spider Bite - These items have no effect on missiles, but can still affect secondary tears created by items such as Mom's Eye and Loki's Horns.
- Technology - The laser becomes invisible, but the firing sound still plays and damages enemies normally.
- Technology 2 - Increases time between Epic Fetus shots. Technology 2's laser only fires between Epic Fetus Shots.
- Like the Fetus in a Jar, this is a reference to Dr. Fetus from Super Meat Boy, one of Edmund's previous games.
- When unlocked and shown on the secret pop up, it's called "Mega Fetus" Instead of "Epic Fetus."