Going off of an old blog for the fusions, from the top down left to right (wall of text incoming):
Gargoyle > Balrog > Devil > Demon
Orc > Ogre > Troll > Trott
Goblin > Hobgoblin > Bugbear > Gremlin
Dragonewt > Wyvern > Bronze Dragon > Royal Dragon
Skeleton > Knight Skeleton > Dullahan > Lich
Great Snake > Storworm > Hydra > King Hydra
Golem > Clay Golem > Large Statue > Talos
Cyclops > Titanoclops > Cleabowans > Argos
Harpy > Great Harpy > Griffin > Phoenix
Slime > Black Pudding > Gray Ooze > Shambling Mound
Androsphyx > Sphynx > Manticore > Chimera
Minotaur > Humbaba > Gorgon > Death Gorgon

The rest are all combinations of the kana that make up each fusion