Reddit mentions of Dinner with a Cannibal: The Complete History of Mankind's Oldest Taboo

It's called Long Pig because the pacific islanders who performed cannibalism only had one other large land animal to compare human meat to, and that was wild pig. No Cattle, no Goats, no Lamb, no horse, etc.

If you want to read a lot more about it, there was a pretty good book written on the subject of cannibalism throughout human existence called "Dinner with a Cannibal", which covers events from the Aztecs, Maya, the Jungles of Africa, to the islands of the pacific, as well as more famous incidents of survival cannibalism, like the Donnor Party, and the plane crash in the Andes.