Fainting goat.
A fainting goat is a breed of domestic goat whose external muscles freeze for roughly 10 seconds when the goat is startled. Though painless, this generally results in the animal collapsing on its side. The characteristic is caused by a hereditary genetic disorder called myotonia congenita. Older goats sometimes learn to lean against something to prevent their falling over, and often they continue to run about in an awkward, stiff-legged shuffle.Via LiftPort alum Jodi Davis
Slightly smaller than standard breeds of goat, fainting goats are generally 17 to 25 inches tall and can weigh anywhere from 50 to 165 pounds. They have large, prominent eyes in high sockets, and exist in as many colors as standard breeds do. Hair can be short or long, with certain individuals producing a great deal of cashmere during colder months. There appears to be no angora strain of the fainting goat.