It looks like only half a fish and weighs a lot. Mola molas can be fairly big.
This is a Mola mola "sunbathing" at the surface of the water. He's soaking up some rays to warm up before he takes a dive into the chilly water. Mola molas like pretty warm water, at least in the double digits.
Ocean sunfish are into jellyfish as their main food source. The sunfish can also act like a plate so other fish and animals can eat little parasites from its body!
Mola molas can also jump really high out of the water! As much as three body lengths!