All Monsters (3)

• Behir - A serpentine monster with a dozen legs that can slither like a snake or move with considerable speed
  Field Guide, OSRIC
• Infernal, Marilith - Powerful infernals with the upper body of a beautiful woman and the lower body of a giant snake
  Field Guide
• Serpent Men - Vile creatures that once ruled the world and wish to do so again
  Field Guide