What is bigger than a blue whale?

Easily possible. It would just have to be some sort of big filter feeder that doesn't get eaten often by other things, and stays in the deep sea. read more

A blue whale is a mammal and the largest mammal on Earth. It mostly eats krill (small shrimp) by swallowing huge gulps of water and then filtering the water through its baleen plates which catches the krill. A whale shark is a fish, the largest fish, and is a filter feeder. read more

The blue whale is the largest animal alive on Earth today, although the exact maximum size is something of a moving target in the literature. This prodigious species is thought to be capable of reaching 110 feet in length, and the largest scientifically verified individuals on record are 89 to 98 feet long. read more