Purple Glitter

Ok, so a while ago I was playing league and I saw a purple glitter next to the murk wolves. It was almost perfectly circular. But I told my team to look at the wolves and see the purple and they all denied it even the people on the enemy team.

I would have shrugged and let it go but about a month ago I was playing league and someone on my team mentioned a purple glitter near the Blue Buff. Has anyone else seen this?