How do I create an object every time the player reaches a new tile and update those objects?

I apologize that the subject heading is a bit confusing. Basically I want the player to create a trail of objects as he moves using the tile movement behavior. I'd also like these objects to detect if they neighbor other instances and update the animation frame accordingly.

I have it working to some degree but the instance variables are updating in odd ways and the animation frames aren't always being assigned.

I'm sure there is an easier way to accomplish this. Any tips would be much appreciated!

dropbox.com/s/us1ccyi40r23ps4/slugtrail.c3p