Sid's mouth though a magnifying glass while he "interrogates" Woody.
"Where are your rebel friends now?"
Sid himself. The way he acts is the telltale sign of a sociopath in the making.
There's a Japanese doll of Woody that comes with two faces you can put onto it. The second face (probably taken from a brief frame of Woody laughing at Buzz in the first film) is... unsettling. It's also become the basis of a rather twisted meme. "You're my favorite deputy" indeed.
Technically, this comes from the Buzz Lightyear of Star Command spinoff, but it's Toy Story related, so it counts. In the pilot movie, the Pizza Planet Aliens are revealed to be united under a single Unimind. Zurg manages to steal it, corrupt it, and use it to spread his influence throughout the galaxy. This is done by giving the creatures affected his voice, his red eyes, and his personality. The sight of Star Command under the influence of Zurg is quite terrifying.