Uriel is a secret unlockable boss fight, accessible after defeating the The Lamb in the Dark Room or ??? in The Chest. After one of these requirements is fulfilled, this boss can be initiated at any point in an Angel Room by planting a bomb near the angel statue or destroying it through other means. Upon defeat, an Angel will drop a key piece required to unlock the large door at the start of The Chest or Dark Room. The defeat of two Angels will also unlock the item Dad's Key.
- Moves towards Isaac.
- Fires 5 blood tears in a circular manner.
- Shoots a single beam of light straight downward, or 2 beams diagonally downwards.
- Because the Angel battle will always be initiated whenever an angel statue is destroyed, Angels can be confronted more than once in a single playthrough. The battle can still be initiated after both pieces of the key are collected, though defeating them after this will yield no additional items aside from a normal pick-up.
- Uriel is one of the archangels of Christianity, and only mentioned from the Apocrypha of the Bible. Uriel means "God is my light".