Ivaldir is the king, or father, of all dwarves. He lives in Dwarf Land amongst the other dwarves.
Ivaldir lost his name playing checkers against the snake Nidhogg, and Nidhogg told him he would only give it back if Ivaldir gave him a jewel made from a metal that didn't exist. However, with the assistance of Thorgal, Tjahzi managed to find the metal and return it to Ivaldir. Thus, Ivaldir regained his name.
Ivaldir and his fellow dwarves later returned to help Thorgal and Tjahzi when they were trapped.