Michael Moorcock's Toad God

[Havard]

Sure, wasn't Averroigne retrofitted there or something?

Not exactly, but there is a connection.

Got to say, though, I personally try more modern approaches:

Like, the way the realm of Mer-Man (OMG OMG) is portrayed in Masters of the Universe makes a sensible background for the Froglers.

Although I have a certain nostalgia for Masters of the Universe, I tend to avoid such comparisons since they will likely only lead to my players cracking up laughing.

When I instead describe Froglin as "originally being humans who have been experimented on, and now appear twisted with bulging eyes and gray swamp-like skin, their hands almost resembling claws", I find that they work better as opponents for the PCs.

-Havard