I Earn "Best Friends forever" advancement, I also earn "A Complete Catalogue" as well.

Well, I was taming a llama and I get the advancement "Best Friends Forever". But I also earn "A Complete Catalogue". The second advancement had nothing to do with what I was doing. The bug could be that I was fooling around with cats in my other world and I tamed like 30 and I didn't get an advancement for taming all cats.