Alchemist Mallory is a level 36 human alchemist and artisan alchemy trainer located in a house in the hills due east of the Stormwind gates in Elwynn Forest. He can be found inside the house, beside Herbalist Pomeroy. Stormwind Guards refer to him as a hermit.
It's possible that the Alchemist Mallory is the alchemist who was forced to fuse with the corpse of a dragonspawn creating Maloriak. However, the names are spelled two different ways, and this Mallory can still be found in Elywnn Forest.