The plate of raw chicken fashioned into a "cake" was the obvious clue that this 112th birthday celebration was slightly different.

The birthday boy is Cassius, recognised in the Guinness World Records as the largest crocodile in captivity. He is 5.48 metres in length and weighs 1300kg.

Cassius, the saltwater crocodile, celebrates his 112th birthday on Green Island. Credit:Tourism and Events Queensland

He is also thought to be the oldest, celebrating his 112th birthday with balloons, a happy birthday sign and the chicken cake at his retirement home on Green Island off the coast of Cairns in far north Queensland.

The saltwater crocodile was captured in 1984 in the Northern Territory after developing a penchant for stealing cattle and attacking boat propellers.