I dont see a problem ^^, you could use the Snake God "Bakunawa" as "Leviathan, Actually in our Country some creatures have different names in different locations/tribes, even different portrayals, so these drawings arent really that 100% accurate.
I cited this in my thesis where some creatures like the Mermaid/Mereman were actually from foreign cultures, we had to treat the variations as different beings despite sharing the same names