The dub for the death screams of the Slayers was taken from the Mahar shrieks in Centre Terre : 7ᵉ Continent (1976).
According to special make-up designer Nick Maley, the special effects character of the Beast was "the first self-contained animatronic suit... providing not only facial movement but also lung, heart and body-fluid movement all without a single external cable! . . .The Emerald Sear transformation puppet, which was intercut with a non 3-D transformation make-up, attracted the welcome attention of the great Dick Smith".
The cyclops says that fire mares can travel a thousand leagues in a day. A league was defined as the distance a heavily armed man could travel in an hour, usually 3 to 4 miles (4 to 7 kilometers). That means fire mares can travel about 3,500 miles (5,000 km) a day, at an average speed of about 145 miles an hour (250 km/h).
Sixteen Clydesdale horses trained for months in order to play the "Fire Mares".