Aw, those are fun! I really like them, and I'm curious as to what inspired you to draw a jack o' lantern/ghost hybridization.
My personal favorite is the one on the left. You made very good use of darker shades of orange with highlights of white to create a pumpkin with real depth. There doesn't seem to be as much colour variation in the other two, but I do like how each one has its own personality.
The dark aura around them, while a simple addition, makes for a nice touch. And WHOA~! Boy, was I ever surprised when I clicked the pic and it enlarged like 10x! These fellows are downright enormous... @ __ @
Very fun stuff, shoKawa! Always happy to see more from you.