Polycerate is a horn mutation causing the horse to have more than 2 horns.

The horns can grow on more locations than just the head, as long as the primary one or two horns are still located on the head.

Polycerate horns can have different shapes (for example straight and curved at the same time), but always have the same type (smooth/twirled/ridged/spined) - you can not have smooth straight and twirled straight at the same time, but you can have smooth straight and smooth coiled.

The primary 1-2 horns should still follow their shape listed in the horn genotype.