How?

Not to mention all his toys had their parts, plus was scuff, scratch, and dirt free. REALLY amazed me.

Not to mention that a Slinky Dog makes no sense what so ever as an actual toy. With a regular slinky you get to push it down steps and stuff. You can't do that with Slinky Dog, you just have this slinky ruined by having two halves of a dog stuck on the end. A real Slinky Dog would just fall over too because the spring isn't strong enough to form a stable base for his four legs. Stand up Slinky Dog! Oh, it's fallen over again. That's not annoying. Slinky Dog defies the laws of physics and defies the laws of actual fun childhood toys. And yet when I saw the films I totally believed Slinky Dogs exist and I just thought I'd never came across one in real life.

Yeah, I can't evan keep one of these sons'a'bitches tangle free for a day!!

With the things slinky does in toy story that spring is supposed to go against hooke's law and not retain it's shape

Maybe he untangles himself. He is alive after all.