Experiment 3C

Experiment 3C is a tortured amalgamation of various creatures that can be encountered as a boss in the single-player experience in the The Witchwood expansion for Hearthstone. During the boss encounter, the entity may mention a lab in Netherstorm, and when confronted with Dr. Boom the experiment will plead for the doctor to not take it back to "the lab", together implying that the creature was created by Dr. Boom at a laboratory in Netherstorm.