Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Tumors are enemies that slowly float across the room diagonally bouncing off walls. They occasionally fire 6 blood shots in all directions, and fire even more quickly when attacked.


Psy Tumor[]

Psy Tumors behave exactly like regular Tumors, but fire homing shots instead of blood shots.

Camillo Jr.[]

Camillo Jr. behave exactly like Tumors, but fire Technology Technology lasers at Isaac. Their lasers may also hit enemies for 8 damage.


Added in Repentance

Planetoids are a variant of Tumor that move faster than their variants and, fire blood shots that orbit them, similar to effect of Tiny Planet Tiny Planet. When they take damage, they fire shots more frequently and have a chance to fart, releasing their orbiting projectiles out of orbit and let them fly off while starting a new ring.


Added in Repentance

Poofers, unlike other Tumors, slowly float toward Isaac and swell up and fire 6 blood shots in a fixed, radial spread each time it takes enough damage. It swells up a total of 4 times becoming slower the more swollen it is. Upon death, it explodes, forcibly pushing Isaac, healing nearby enemies for 15 HP, and leaving a large puddle of damaging Red Creep.

Their health also doesn't deplete until they are hit by a total of at least 40 damage, giving them an effective health of 60 and a unique form of one-shot protection.


Swarmers are a variant of Tumors that do not fire projectiles, instead they will spawn fly monsters. It will occasionally spawn Attack Flies while floating, when hit it will spawn a Pooter, and when destroyed it will spawn a Boom Fly. Unlike other Tumors, Swarmers do not deal contact damage.



  • As Swarmers have Champion forms it's possible to encounter a White Champion (though extremely rarely). This can be a challenging occurrence as the Swarmer will regain invincibility every time it takes damage due to spawning Pooters.
  • Skatole Skatole will charm a Swarmer. When charmed it won't spawn any flies until it is damaged. The flies that spawn will also be charmed.


  • Tumors are a reference to abnormal growth of tissues of the same name, caused by genetic mutations.
  • Camillo Jr.'s name is a reference to Kracko Jr., a recurring enemy from the Kirby series. In appearance he bears resemblance to Kracko, another recurring enemy from the Kirby series.
  • Swarmers are the next and possibly the final stage of the original Gaper.[1]
  • The ring of Flies that surround the Swarmer is an indication of how much health it has. The Flies deplete as the Swarmer takes more damage.
  • Added in Repentance Poofer is a reference to the enemy from The Legend of Bumbo with the same name.
  • Added in Repentance A Planetoid is an astronomical object that is neither a planet nor a comet.