I forget what it's called, but it's where you lay on the floor, on your stomach, and you reach your legs, and curl your back, so your legs dangle over your head, or are on the ground on either side of your head. Does anyone know the name of this?

It is a contortion move rather than strictly a gymnastics one. It is called a scorpion which is confusing as that it something quite different in cheerleading. Many coaches discourage gymnasts from doing that because of concern that if it is stored in muscle memory it may become an accidental landing position which could cause serious injury.

Basket or birds nest?

a basket?

I think its a chin stand. they are on their chin right