Quoted By:
Britbong here.
As far as mythical creatures go, the only major ones I can think of are hellhounds, Gyn Annwyn (which are the original celtic equivalent) Griffins, gargoyles and of course, the dragon that St george slayed / became the emblem for welsh flag.
That said, theres room for a shitton of fairy + x dual types, since celt and arthurian mythos has a lot of fae involved.
They will probably use norse mythos as that has far more animals used in it's tales.
