When all 6 different Bobblehead pets meet they can do several dances.
There was a bug where if Ahrim is placed in the player's menagerie, he will show a yellow dot on the minimap even though other pets do not show this. In addition, attempting to interact with him will result in the "Nothing interesting happens." message, even if the said person is his owner. This was eventually fixed in a hidden update.
Ahrim the Bobbled was given the ability to override summoning familiars on April 32018.