How do you get those? I don't think I've encountered gryphons or dragons in the game. Then again, I haven't tried freely exploring the world yet. I guess dragons are near dragon breath volcano in the south west part?
Ralph, in the Dominion shopping area, sells a Gryphon TF food item called Pate' and crackers, the icon is blue. Quick, easy, and no hassle to acquire.
Gryphons
can spawn in Domion, but they are extremely rare, otherwise the areas where they would normally spawn don't exist in the game yet.
The dragon TF food is sold by a vendor in Elis ... That is only available from the 1st to 3rd (maybe 4th) day of each month AND you have to go through some stupid quest that will take an in-game month to complete or more if you don't start it early in the morning on the 1st day of a month.
Dragons will not spawn in the game normally. The areas where they are designated to spawn, do not exist in the game right now.
If you really want a dragon TF, just use the debug command BUGGY and spawn in a couple dragon TF items.
As, Draupnir7, said, you can transform yourself in to a slime and transform yourself into whatever form you want and then enchant a bio-canister with the turn to flesh enchantment and turn yourself back to 'normal' and instantly be whatever race you were imitating as a slime.