Happy Feet – the homeward bound penguin which was released at the Southern sea of New Zealand is missing in action since its release.

According to a report by The Associated Press, Sirtrack, the company that attached the tracking device to the popular emperor penguin said the device stopped transmitting since Friday.

The most likely scenario, according to experts, is that Happy Feet’s transmitter fell off.

Other possibilities are that Happy Feet might have been eaten by an orca whale or a leopard seal or that he died of natural causes or that the transmitter malfunctioned.

Happy Feet was discovered on a New Zealand beach last June. He was nursed back to health at the Wellington Zoo before he was released back to the ocean.

Initial reports from Happy Feet’s satellite tracker showed that he swam in a spiral route, ending up about 75 miles (120 kilometers) southeast of where he began when the last transmission was received Friday morning.