Well, since I couldn't decorate the chain collar, and was afraid that if i did anything to the flea collar, it would stop working, I made a dog tag for him. That way he can have my phone number on him in the unlikely case that he gets lost. And so, without further ado, here it is. :)

Nemo!

It's made of nail polish on top of a bit of plastic. The phone number is on the other side. :)
And unlike his previous dog tag, this is small enough that it doesn't bother him.