Does any class NOT extend Object?

Just as a technicality, is there ANY object (or anything that can be placed inside of a variable) that does not extend Object?

Even the “Class” object extends Object.

On a similar note, what is the difference between these two?

var unknownObject:Object = getItem();
var unknownObject:* = getItem();

I pretty much always use “:Object”, but is there any situation where it would be better to use the latter?

I also recently found out that there is a difference when using the “as”:

myObject = (unknownObject as Object); //Works
myObject = (unknownObject as *); //ERROR