J here with a few small projects using those mini pumpkins you can find at grocery stores this time of year. With inspiration courtesy of remodelaholic.com and marthastewart.com we built some variants on their tealight candle pumpkins and Drac-o-Lanterns.
-A sharp knife, X-Acto #11, or pumpkin saw
-For Drac-o-Lanterns: Fake vampire teeth, map pins, white pony beads
-For Tealight Pumpkin: Tealight (we used the battery version), OPTIONAL: Toilet paper tube, tape
-OPTIONAL TOOL: Corkscrew
Using your plastic teeth as a guide, mark how wide a mouth you will need on your mini pumpkin. Cut out a mouth-shaped hole in the pumpkin's "face", lower on the pumpkin. I went with a slight "smile" on the corners, but your mileage may vary. Wedge (sorry, "test-fit") the teeth into the mouth and see what else needs to go and get all Mad Dentist on your little guy or gal or thing until you like the fit of the teeth. (Martha suggests using a template for this part, but where's the fun in that?)
Once your choppers are installed, you'll need peepers. Colored map pins or sewing pins work wonders, but may not be enough on their own. Consider leaving the pins extended by a quarter inch and hanging pony beads on there for a more googly eye. Personally, I can't look at that little guy's face and not crack right up. He's just so excited! I went red with white, but black and yellow would be spooky, and black and white is just fine.
From experimenting with other pin colors, I had extra pins on hand that Cat wanted to put in his mouth (dumb Cat) and so I used them as little 1950's TV legs to prop his face up a little. That's up to you. Here he is again:
You may recall the Tealight Glamourshot as our initial image here on With Our Powers Combined. If so, good for you. If not, we'll get to it.