Its basically a throwback to earlier editions. I suspect that old time players love them most of the time. That said there was some kind of a frog fixation in the early years of the game. Frogs show up in adventures of every level far more then could possibly be attributed to random chance.
In fact I suspect one could - if one put their mind to it, run an entire campaign in which the players never met anything that was not a frog.
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See, the thing is, all the frogs are semi-iconic for the game ...
one of the original "Creator" races was batrachian. So, all the frogs and frog-like creatures are 'carry-overs' or 'throw-backs' to that time.
makes a kind of sense when looked at in that light, eh?