Dog

Dog is an animal found in the Kingdom of Alpoko. It joins the kingdom after the Onii Man is defeated.

The dog is one of the animals saved during Shizuka's special quest, saved from the western path of Skull Plains. 

According to unused letters from Omelet, the dog is a friend of Shizuka's, and his name is John. He was originally going to dig up the Diamond Egg (called the Golden Egg in beta) in the Worrywart Kingdom during the God UFO quest, before the requirements for the quest were changed for release.