Related Clues:

• Deranged
• Crazed
• Maniac
• Zealous devotee
• Fervid follower
• More than enthusiastic
• Recklessly foolish
• Fervent one
• Many an old horror film scientist, e.g.
• Asylum occupant
• One who's more than devoted
• Monomaniac
• Extreme enthusiast
• Excessively devoted
• Zealot or extremist