Amphibian Man

The Amphibian Man is from the 2017 Guillermo del Toro movie The Shape of Water.

History
The Amphibian Man is seen very briefly hiding in the floorboards under Lisa Simpson's bedroom. He is holding an Oscar trophy in his hand, which represents the award the movie had won. This is also a long running gag in the show where they the audience sees strange oddities hidden in the foundation of the Simpson's house.