After Perseus saves Princess Andromeda and the two are washed up on a beach, her arms are still cuffed to long ropes. As she stands to her feet, they vanish from her arms instantaneously.
Bubo the owl from the original Clash of the Titans makes a brief appearance when the soldiers of Argos are putting together their supplies and arms for the trip to meet the witches. Perseus picks up a staff out of a chest of assorted weapons with a mechanical owl atop of it and asks the Captain "whats this?" the Captain replies harshly "Put it back!"