### Clue: He often helps a mad scientist dig for missing heads (4)
### Answer: IGOR 
 ### Explanation: Definition: He often helps a mad scientist
 "dig for" **minus their respective 1st letters**(missing heads).
Defn: The name, derived from and reinforced by pop culture, that represents, in the public imagination, one who helps a mad scientist, such as Dr. Frankenstein and other horrific villains. It was first used in the Frankenstein movies based on the Mary Shelley novel, although there was no assistant in the latter.