Level 15 F Path

On this level you are asked to guess what is blocking your way on through the pipe, you get a poem to guess it:

You wish I was normal, small
Round as now but not a ball
Wish my color was like me
When I left my home, my tree
Aneninen loves my taste
Even likes to smell my waste
Number fifteen helps you guess
Say my name I let you pass!

Curiously when we took the image and copied it on our desktop the image inverted colors and we saw this:

Well... nothing more to say... we hope you got the answer!