Maybe the frog is a local symbol at both universities I attended.
I know ZTA had a local mascot for their chapter besides the 5-point crown.
Saw several items like these online:
Sorry for any confusion with KD. I see the frog on AKA items too, but it may be local or unofficial, as it's not mentioned on their website.
Couldn't find any nautilus shells on The Liquidation Channel website, but there were many choices of white roses, bears & shamrocks (with the last symbol mostly around St. Patrick's Day).