The Once-ler costume is shown here done very well from the Dr. Seuss movie The Lorax. The Once-ler is voiced by actor Ed Helms from The Office (US version) fame and bachelor party movie favorite The Hangover. This costume is a perfect rendition of the character from the movie and book with a big top hat, green suit, green sunglasses, green gloves, and green pants. The Once-ler costume here utilizes many shades of green which pulls the look off quite nicely, taking a cue from interior designers on color matching. The Once-ler costume is supposed to be a boy with short black hair so this costume-goer shoes off the costume perfectly. The boy also wears a fluffy pink pin on his lapel, perhaps to symbolize the Truffula trees that he chops down to make thneeds.