Apis was the sacred bull worshipped at Memphis in ancient Egyptian religion. Egyptians treated the living bull as a manifestation or herald of the Memphite creator god Ptah, giving the animal an unusually prominent place in temple worship.
A new Apis bull was selected according to distinctive physical signs, traditionally including a black coat and particular markings. The bull lived at the temple in Memphis, where priests observed its behavior and interpreted it as an oracle. When it died, the animal was mourned and given an elaborate burial before a successor was identified.
The Apis cult changed over time. Apis was first associated with Ptah, then increasingly connected with Osiris after death; the composite deity Serapis became especially important in the Greek and Roman periods. The famous Serapeum at Saqqara contained burials of many Apis bulls, so Serapis is related to the tradition but is not the name of the sacred bull itself.