Does he look like a purebred chihuahua?

Mostly Chi, maybe all Chi. Jack-rabbit looking ears, but cute! I'd have a vet (or vet-opthamologist) examine those eyes. There might be some irritation from extra eye lashes that are turning inward & rubbing the surface, or follicular conjunctivitis, which is fairly common in puppies. You can get some drops to treat the latteer or the vet might simply pluck the lashes under a local. 50% removed that way, never return to bother the dog again.

He looks about 3/4 with some Jack Russell. I love his ears.

Nope. He could have some terrier in him.

No but he is so adorable

No. I agree that it looks like Russell Terrier or some other smaller, stocky terrier in their.

If this was a real Chihuahua you would have gotten a PEDIGREE from it and would have gone to an AKC registered Chihuahua breeder. Chihuahuas are one of the most overbred/illbred dogs these dogs so VERY few are really Chihuahuas. Most are either mutts or bred WAY too small.

Almost!something not quite ! Maybe crossed with a small terrier!