Dragon: Tapered, Knotted, Draconic.
Horse: Blunt, Flared, Sheathed, Equine.
I'm not sure how well they mesh. You may be thinking Gryvain.
Gryvain: Tapered, Knotted, Ribbed, Scaled, Gryvain.
That said:
Knot A Problem and Bumpy Road already exist (Knot/Nubs). Turtleneck Cream can add Foreskin or...