Rift scuttle and trundle
When watching LCS I noticed that trundle pillar makes scuttle stand still. I think placement of the pillar is important to trick the rift scuttle but it seems like an interaction that shouldn't exist.
It's a huge buff for the Trundle players who know about it and use it, but most of us average joes who play the game don't even know about the interaction and/or aren't aware of the right pillar placement. In my opinion this type of unintuitive reaction on the scuttle crab should change.