"Dungeon Chest" from new CTA reward display bug? (Mini-Garrundar the Vile)

While doing the 10 daily runs for a token, I noticed that after accepting the dungeon chest I was rewarded on the right hand side of the screen with a purple "Mini-Garrundar the Vile". After leaving the dungeon and checking the item spot that a new thing would go to, I found an "Alliance Battle Horn", which I had another of that was still in the same spot. I googled the name and found that this is a pet. (I hoped it was a mount:() I was unable to find it in my collections, not even listed let alone collected. Perhaps it's just a display glitch and if it were available it would have been a reward if it were actually currently available, or a one-off thing that happened to me and it can be obtained.

With that said, has anyone else experienced something like what I described? Can you find it in your collection books? Have you gotten it?