Hornfel

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

• Hornfel will sometimes taunt Isaac by sticking out his tongue while sending out his decoy dummies.
• Hornfels is the group name for a set of contact metamorphic rocks. They are known to be very hard and durable.
• The Horny Boys are a stitched amalgamation of Hornfel and Loki.
• Hornfel and Loki are siblings.[1]
• Allowing for Hornfel to escape the room will only increase the amount of times you've encountered him.
• This will leave the amount of times he has been killed the same, similarly to Baby Plum only having her encounter rate increased if allowing for her to leave except without any extra rewards being given for "sparing" hornfel.