Binding of Isaac: Rebirth Wiki

Added in Repentance

Tuff Twins is a boss added in The Binding of Isaac: Repentance that can appear in the Mines Mines.


Tuff Twins always spawn in a pair consisting of 5 body segments and a head segment each. They are always fought in a double-sized room.

  • The Tuff Twins roam around the room randomly, like Larry Jr. Larry Jr.
  • Normally invincible, but bombs and explosives can destroy their stony exteriors (after 15 damage per segment), making their segments vulnerable.
  • Head segments spit Ink Inks while protected by its rock armor.
    • Vulnerable head segments spit Sucker Suckers instead.
  • Vulnerable body segments spew bloody shots, similar to Boil Boils.
    • When a flesh segment is killed it spews blood shots.
  • Tuff Twin segments can be split into smaller copies of the boss as long as the new Tuff Twin segments are longer than 2 pieces.
  • The Tuff Twins become faster the more rock armor they lose.



  • Terra Terra, along with any items that create rock waves like Mega Bean Mega Bean and Wait What? Wait What? can destroy the Tuff Twins' armor.
  • Neither Fire Mind Fire Mind explosions nor Sulfuric Acid Sulfuric Acid tears can destroy their armor.
  • Killing all the Bomb Grimaces with effects like Little Horn Little Horn and Euthanasia Euthanasia can soft-lock Isaac in this fight.
  • Plan C Plan C cannot kill the Tuff Twins if they still have their armor. (Possibly a bug?)


Bug Bug! tuff twins can get stuck with the bomb grimace in the room


  • They appear to be a rocky variation of Larry Jr.
  • The Shell The Shell appears to be the posthumous version of them.
  • Tuff is the name of a type of rock formed from volcanic ash.