In QA I tested letting a tamed squeaker die. After the five minute timer finished, the taming necklace still said squeaker on it. But, I was able to tame a rabbit over it, and then it said rabbit. When the five minute timer finishes, the necklace should stop saying "squeaker" and become blank like a brand new taming necklace. This was in patch 839. Sorry I didnt get the slash devbug for this. It was a random encounter.