Some eyes for Enderman! His natural eye colour appears to be purple, and he looks less friendly without them...so I created some 'snap' in eyes. The STL included here will produce one set - I suggest that you print four sets on the same job though as they print so fast that you will get blobs/strings unless you slow down the job considerably.

As they are in the STL at 100% they will fit in the original model as is.

I have scaled them to 150% for the size of the model in my pictures and they fit fine.