Puffins are related to Rhinoceros Auklet which are type of birds, not Rhinos!

An auklet is any of a variety of seabirds in the genera Aethia, Cerorhinca and Ptychoramphus.

Most likely small fish.

Rhinoceros is a genus which contains two species:

Indian Rhinoceros - Rhinoceros unicornis

and the Javan Rhinoceros - Rhinoceros sondaicus

The Atlantic Puffin, the Horned Puffin, the Tufted Puffin, and the Rhinoceros Auklet are the four types of Puffins in the world. Puffins live in the North Atlantic Ocean, Europe, France, Iceland, Greenland, and Northern Russia. About 60 percent of the world's Puffin population live in Iceland.