The Liopleurodon's concept art shows a generic liopleurodon the size of Kamoebas with a smooth, white underbody and a darker-colored pattern on the top of its body. It had a row of sharp teeth, as well as large, crocodilian jaws, and four fins.
The Liopleurodon would have washed ashore, having been killed by Godzilla. The carcass would be investigated by humans and it would be determined that Godzilla had killed it.
The Liopleurodon was a concept that was created to replace the concept of Anguirus being the dead monster that washed ashore. However, the Liopleurodon was scrapped due to Toho not wanting to introduce a new monster just to have it be dead from the start, so it was replaced with Kamoebas, whom wasn't as popular as Anguirus.
- According to Godzilla X Mechagodzilla X Mothra: Tokyo S.O.S. Fantastic Collection, the Liopleurodon was the first monster conceived to be washed up on the beach. Anguirus was considered second, and then Kamoebas was third.