Need some input on what type of pan the top is made out of? Thanks

It is the 2nd cake in the link - it's Kai lan (her round ball type face on a tier)
http://www.birthdaycakesblog.info/ni-hao-kai-lan-birthday-cake-2.html

You could use something like a rounded bowl or the wondermold pan, both carved down. Or you can just bake some rounds, stack them and crave them down to the shape you need them to be.

i would use pyrex bowls and stick the two halves together with buttercream to make a ball

I don't think the bottom half of her "head" looks that rounded to me. That looks like a regular cake that is just carved down a bit.

Thank you all for your help! I think I am going to try putting a bowl on top of a cake round and kind of carving it together.