A Mulliboom is another alternate form of the Mulligan. It is commonly found in Chapter 1-3.
Beside their appearance looking identical to normal Mulligans, Mullibooms have a bomb wedged into the right side of their head and cry blood rather than actual tears.
Instead of avoiding the player like their other variants, they will charge at Isaac and explode on contact, dealing 1 half heart of damage. They also explode immediately if they are killed, similar to Boom Flies. Make sure to keep a safe distance when delivering the final shot, and consider killing them next to a wall that might be adjacent to the Secret Room.
- They appear in the Wrath of the Lamb DLC for the original game.
- From the original game, explosions from Mullibooms originally inflicted one full heart of damage. After many complaints about layouts where avoiding damage seemed impossible (which on the Basement often resulted in frustrating deaths), Edmund reduced their damage to 1/2 heart. This makes their explosions the only kind that does not inflict a full heart of damage.
- In the original game, Mullibooms' eyes are smaller. In Rebirth, however, their eyes are larger, compared to the Mulligans.
- This is the only known type of Mulligoons to chase after Isaac rather than fleeing from him.