Answer: hippopotami

AnswerCrossword Clue
HIPPOPOTAMIOn Sandra Boynton greeting cards, they symbolize the word "Happy"
HIPPOPOTAMITough-skinned mammals
HIPPOPOTAMIGroup that's called a bloat
hippopotamiA large thick-skinned semiaquatic African mammal, with massive jaws and large tusks
hippopotamiHIPPOPOTAMUS, a large African artiodactyl ungulate of aquatic habits