Scarlet's Game Room
I know of 4 creatures that drop Minotaur. There could be more, I don't have the scoop on ALL the bosses out there yet. I been trying to get Digby to do my work for me - uh, I mean HELP me, but I haven't had much luck yet.
Hamakala's Mausoleum, Krokotopia
Pagoda of Harmony, Krokotopia
Tree of Life, MooShu