Mom is an enemy in The Binding of Isaac: Rebirth that is present as the official final Boss of both The Depths II/XL and Necropolis II/XL.
Mom is a unique boss in the fact that she rarely shows herself and mainly uses spawned Monsters to kill Isaac. One cannot see Mom's full body, for she appears to be outside of the Boss Fight Room, therefore not allowing her to have movement patterns. Her main weakness is The Bible, for, if The Bible is activated during the Boss Fight, Mom will die. Mom's attack behaviors are as follows:
- Mom will randomly perform one of the following attacks:
- Mom will shove her eye through the door, dealing contact damage to Isaac.
- Mom will shove a lump of her flesh through the door, spawning an enemy that was not in The Wrath of the Lamb DLC.
- Mom's foot will hover over Isaac's position when the attack initiated, allowing the player to foresee where her foot will land due to the location of the shadow. Mom's foot will then stomp down on the location and deal explosive damage on landing.
- If Isaac is too close to a door, Mom will thrust her hand through the door, dealing contact damage. The player should note that Mom's hand reaches out much further than her eye/flesh.
Mom has a chance to spawn as one of two Champion Variants. Her Champion Variants are as follows.
- Mom will be red. She will not spawn enemies but rather frequently stomp and thrust her hand at Isaac. When she looks into the room, she will shoot projectiles in a tri-pattern.
- Mom will be blue. She will only spawn Monsters from The Wrath of the Lamb DLC. She also summons Monsters more often than usual.
With the correct items, the player can easily defeat Mom. The Bible, as stated above, will kill Mom instantly upon use. The next best thing would be for the player to use Isaac's orbiting familiars (Cube of Meat, Sacrificial Dagger, etc.) against Mom's leg after it has landed. Another method is to use Midas Touch. Mom's foot actually touches Isaac before it deals explosive damage, allowing Isaac to freeze Mom's foot without him taking any damage. One last strategy against Mom is to have Pyromaniac. This way, Mom's foot cannot damage Isaac and actually has a chance to heal him.
Another strategy the player can employ is to stand beside one of the doors (commonly the bottom one) and attack the eyes/hands/flesh that pop through to deal substantial damage. This works especially well with high-damage orbitals to increase DPS. Because the player is standing against the wall and close to the door, Mom's foot will not stomp; Isaac himself should be positioned just far enough away from Mom's extremities to avoid taking any damage from her door attacks, as well. The only threat at this point is being targeted by an enemy - with luck, however, they may spawn in such a location as to ignore Isaac entirely. Because this strategy requires very little skill, some may consider it a cheap win.