Thorn causes a combination of extreme claw growth on all claws, and extra digit growth on the wings. 

You may choose to only show either the extra digits or the overgrown claws! 

Thorn may appear randomly in breeding, or may be passed down from a parent which has it. You may freely draw custom lines for it, and please check the bottom of the page for pointers and ranges!

The claw growth of Thorn follows Keratin rules, and can display all the color options listed there. Markings can appear on Thorn's claws as usual, as detailed in Keratin rules. 

When drawing your own Thorn, keep in mind that the main effect is extreme claw growth! These may appear somewhat straight, like male terrapin claws, or curved such as cat claws. Up to one extra digit per wing may be added; more would need an Extras mutation! Thorn can, however, affect claws added by body types such as Finned, and can add claws to the tips of fins which don't usually have them.