Growth on back leg

by Capn
(Utah)

Hello,

My rabbit has a long stick-like growth protruding from his back leg. It started out looking like an injury, then a scab that just kept growing longer. It is stiff and he jumps when it is even lightly touched. I have searched and searched and have not been able to find an answer. Does anyone know what this is?

I am grateful for any insight you can provide.