It's unlikely but possible, several species of Sharks would be able to swallow a puffin.
probalbly a dead one
yes
who is puffin?
yes
No. They eat fish and zooplankton.
puffin's may be eaten by a falcon or an eagle.
Yes you can. But most people tend not to. Here's an Icelandic recipe for Puffin in milk sauce: http://icecook.blogspot.com/2006/07/puffin-in-milk-sauce-mjlkursoinn-lundi.html
nope
A leopard seal.
The main diet of the Horned Puffin is fish. They also eat squid and zooplankton. Adult puffins can dive over 80 feet in the water to catch fish.
A leopard seal.
Yes a seal does eat fish.
Large puffins cannot eat puffins or puffin eggs. They do scare puffins and annoy them but only to make them drop their fish that they have caught. They really do not eat the puffins; they just want the fish that they have caught.
seal, whale, and caribou mostly