Dolph is a gray hippopotamus of great size and a large build. He has a huge mouth and teeth characteristic of his species, and black beady eyes. He is usually seen wearing casual clothes, which consist of a white or black T-shirt and red sports pants during drama club activities.
Dolph has been seen to have a meek, very patient and calm demeanor. He shows no discomfort or nerves when it is mentioned that he is a carnivore or when Legoshi openly reveals suspicion of him and the other carnivores.
- He shares the same name with Dolph the Lion from the Shishigumi. Whether this was intentional or a mistake on the author's part is unknown.
- Despite being introduced in the first chapter, his name is not revealed until Chapter 59.
- In the Beastars universe, hippos are classified as carnivores. However, this is wrong as they are herbivores whose diet in the wild consists almost entirely of grass, with minimal consumption of aquatic plants.
- However hippos have been known to eat meat, even cannibalizing other hippos.