Rare find- vintage 1960s Oklahoma-based FRANKOMA pottery TCU purple Horned Frogs "C-1 mold" stoneware mug.  Older purple horned frog football mascot against grayish-white glaze on a stoneware body, 4-part segmented bottom rim. Unfortunately chip on one unglazed foot but still super cool vintage find. 

4" high, 4.24" width including handle, 3" diameter opening. Display piece, no stains, spoon marks, scratches. Only flaw is shallow chip on foot- see photo.