A group of Hippopotamuses is called a Bloat.
The plural of Hippopotamus may either be Hippopotamuses or Hippopotami, your choice.
Hippopotamus comes from the ancient Greek for "river horse" (ἱπποπόταμος).
This Hippo may be used for the following cosplay:
Dr. Abby Sciuto (Burt, NCIS)
Age: 24 Months and up