I currently have 2 sporeking trophies in my inventory because for some reason he respawned, BUT I cannot complete the quest even though the quest says to claim the bounty. The bounty hunter doesn't have the option to complete. This is the last bounty and I am stuck because of it.

Same situation 

Same here, hoping for a patch as my backup save is 5hours back

It has happened to me as well. When he respawned, I was unsure if I looted his body. So I killed him again out of reflex. 5 hours later go to turn in my bounties and I realized that I have 2 sporeking crowns.

Have the same problem. New patch 1.2.3 does not fix it. Submitted report to the support email as well.