Judas

Judas is a character unlocked after beating Satan for the first time. Judas starts with one red heart container, but has upon starting, as well as 3 coins.

Dark Judas
When a character dies after picking up the item, they will respawn as Dark Judas. Dark Judas spawns with two black hearts, a damage multiplier of 2.00 (instead of Judas' 1.35 multiplier), and a base speed of 1.1. Dark Judas has the highest base damage multiplier of all the playable characters.

Similar to, Dark Judas can still gain heart containers despite starting with none.
 * Similar to, Dark Judas is unable to obtain heart containers. Any health-up items he collects will grant black hearts instead.

Dark Judas is considered by the game to be a separate character from Judas, but all of the Judas Completion Marks on Judas' post-it note can be completed with Dark Judas and unlockable items and/or achievements can be earned by completing objectives with Dark Judas.

Item Interactions

 * : Currently unimplemented for both versions of Judas.

Good Items

 * : Synergizes with Book of Belial for an extra 1.5x damage multiplier.
 * : Due to his low health, Judas can easily take advantage of Whore of Babylon's effect.

Trivia

 * Judas is a reference to Judas Iscariot, the Twelfth Disciple of Jesus Christ. Judas betrayed Jesus to the Romans in exchange for thirty pieces of silver, represented by the three coins Judas starts the game with. Moreover, the coins are also believed to represent the three Abrahamic faiths, Judaism, Christianity, and Islam.
 * Contrary to popular belief, Judas's fez is not a reference to the game Fez, created by Phil Fish. Edmund Mcmillen has stated that the initial statement was a joke and that he used the fez due to it being easily recognizable.
 * In the original Binding of Isaac, Judas was unlocked by beating for the first time. The character unlock was replaced with unlocking  in The Binding Of Isaac Rebirth.