An achievement/Advancement called "Betrayal"

So this is an achievement you get from killing any animal you have befriended. This is an awful thing to do and you should be shamed on by saying some like "you would sacrifice your friend just to get this achievement! You monster." Or something like "how could you do something so cruel you monster" idk something like that. But idk about the first one. P.S. idk how to categorize an achievement.