Six years old, and at the prime of his life, Odin lives at the Six Flags Discovery Kingdom Zoo in Vallejo, near San Francisco. He is about 10ft long from nose to tail, and is an excellent swimmer.

Odin was hand-raised at the zoo. And after he was weaned, his British trainer Lee Munro discovered his remarkable skill: when a lump of meat was thrown into a pool of water, Odin would happily dive in after it.

In fact, although Big Cats generally do not like water, tigers of all types have been spotted taking to the water to hunt and even to bathe for pleasure.

Odin can now be observed in action - a large pool with glass walls has been constructed at the zoo to allow visitors to watch him gliding through the water with all the grace of a polar bear.