How did you carve the top of the mushroom 

Drew a design freehand and shaped it with a Dremel and various bits

 what type of paint did you use for the black? 

Black and white Valspar rattle can spray paint and Minwax spray poly, anything for wood should work

You don't always get what you go after,but you do get what you wouldn't have got if you didn't go after what you didn't get. Blaze Foley