Checking if an entity touched another?

Hello, I'm working on a pretty cool plugin that would allow for some awesome parkour games, I'm looking for a method to check if the player is literatly touching another entity. Basically, I want to make it so that if a player runs into a creeper (NOT CLICKING IT), something could happen.

 

Hm.. Interesting idea. Only way I could think to do it is every move event check if another entity is at their location, but that is hardly efficient, and will cause lag, as it is running almost all the time.

 

I wish there was a collide event xD

 

Only thing I can think of is checking every playermoveevent and checking the nearby entities within 1 block of the player (or less if possible) but that would be quite intensive.

 

EntityHitByEntity?