- Tricephaly, in which an animal is born with three heads
- Tetracephaly, in which an animal is born with four heads
- Pentacephaly, in which an animal is born with five heads
Polycephaly is caused by a variety of factors, including genetic mutations, environmental factors, and developmental abnormalities. In some cases, polycephaly is fatal, but in other cases, animals with polycephaly can survive and lead normal lives.