I would like to make some sculpted rice crispy characters but Im not sure where to start. Ive seen on cake boss where they have the rice crispy cooled but I thought that once its cooled it wouldnt be moldable. Can someone please give me some tips? Thank you!

As long as it's cool enough to the touch you can begin molding with it. The more it cools the more it sets up. If you have some left over that gets too stiff, just nuke it for a few seconds to soften up the marshmallow again.

I find that what works best for me is that after I get my shape, I give a good coating of candy melts to really set the shape. Even on the hottest days it stays intact. Plus, when I add enough it fills in the gaps and I need less to get a smoother finish when it's time to cover it with fondant.

Good luck