It's not pink goop. It's more like a beige-ish sludge. Gross? Not entirely because ground up raw chicken meat made on a mass level will probably never look appetising, no matter how clean the process and how delicious the result is.
McDonald's Canada recently addressed what's actually inside a McDonald's Chicken Nugget and it's not as exotic as we were afraid to believe.
It starts with a whole chicken which is sliced up and separated into their specific cuts. Chicken breast is separated and collected into a bin. The bin o' chicken is then ground up and chicken skin and seasoning is added to a meat blender. The blended chicken is then shaped into the four official chicken nugget shapes and dabbed with a light and heavy batter. It doesn't exactly look good when it's made (as you'll see below), but it's still chicken.