Goodie Bag

The Goodie Bag is an item which drops during the Halloween seasonal event (October 20 through November 10) that gives you one item chosen at random from the list below, similar to Presents and Crates. Most are vanity items and decorative furniture, the exceptions being the Bat Hook, the Rotten Egg, and the Unlucky Yarn. Goodie Bags are dropped from any enemy other than statue-spawned enemies or Meteor Heads, with a 1/80 or 1.25% chance, during Halloween only. The most common droppings from the goodie bag are Rotten Eggs.

Trivia

 * Many of the vanity sets are references to popular culture. The Creeper set is in reference to the indie sandbox game Minecraft, the Space Creature set is in reference to the xenomorphs from the film Alien, the Karate Tortoise is a play on words in reference to Teenage Mutant Ninja Turtles, the Leprechaun set is a reference to reports of a leprechaun sighting in Mobile, Alabama, | Reddit post by Redigit, | Remix of the report that Redigit looped while coding, and the Bride Of Frankenstein is referencing the film The Bride of Frankenstein.
 * The "Jacking Skeletron" painting is a reference to The Nightmare Before Christmas, in which the main character is Jack Skellington. The scene depicted in the painting is of Skellington at an iconic location from the movie.
 * The theoretical average amount of enemies a player must kill to get every drop this item can produce is ~1.08 Billion enemies.