Finn's pack is a green backpack that Finn wears during his adventures through the Land of Ooo. In addition to containing basic adventuring gear, Finn's pack often doubles as a seat for smaller characters so that they do not need to walk. After his original pack is destroyed in "Mortal Folly," Finn gets a new backpack in "Mortal Recoil" made by Raggedy Princess and other princesses.
The pack is round and green, with a lighter green flap that unzips along the top. The pack is somewhat elastic in that it is capable of expanding slightly and has a large carrying capacity, as it was able to hold all of Stanley's family (with the exception of the four marshmallows and a watermelon). Recently, there seems to have been a strap added to the pack which was used to hold Finn's Root Sword or Demon Sword.
Finn is almost always wearing his pack while adventuring, dancing, playing video games and even swimming. He occasionally goes to bed while still wearing it. The pack appears in the opening sequence and is worn in almost every episode.
Episodes in which Finn does not wear his pack
- "Trouble in Lumpy Space," after Finn turns completely lumpy.
- "Business Time" (while using the flame thrower)
- "The Creeps"
- "Evicted!" (while in his pajamas, and while "chillin' on the side of a hill")
- "The Duke" (while impersonating Princess Bubblegum)
- "Power Animal" (when captured by the gnomes)
- "The Other Tarts" (while carrying Princess Bubblegum's Anti-gravity tote chamber)
- "Her Parents" (after falling through the roof, and when Finn is being "eaten" by Bob and Ethel Rainicorn)
- "Go With Me" (while wearing the Lute suit)
- "Mortal Folly" (after the pack is destroyed)
- "Mortal Recoil" (right before the princesses made him a new one)
- "Hitman" (while Jake is making his sandwich made with meat man's meat)
- "No One Can Hear You" (after Jake breaks Finn's wheelchair)
- "Another Way" (when the clown nurses are taking care of Finn and Jake)
- "Who Would Win"
- "Lady & Peebles"
- "Simon & Marcy"
- "Is That You?"
- "The Pajama War"
Characters who have sat on or been in Finn's pack
- Tree Trunks
- Marceline (in bat form, and was inside pack)
- BMO ("Candy Streets")
Finn's pack is known to contain, or to have contained, the following objects:
- Bells ("City of Thieves")
- Binoculars ("Adventure Time," "Prisoners of Love," "Ricardio the Heart Guy," "Donny," "The Chamber of Frozen Blades")
- Ble comics ("Incendium," "In Your Footsteps")
- Bug Milk ("It Came from the Nightosphere")
- Demon Sword ("Dad's Dungeon," "Return to the Nightosphere," "Daddy's Little Monster," "Beyond this Earthly Realm," "Gotcha!," "All the Little People")
- The Enchiridion ("In Your Footsteps")
- flute ("Prisoners of Love," "Gut Grinder," "Too Old")
- Garden hose ("Red Starved")
- Glue ("Loyalty to the King")
- Gold Sword ("Business Time," "Tree Trunks," "Loyalty to the King," "The Pods," "The Silent King," "The Real You")
- Grapes ("The Jiggler")
- Groucho Glasses ("Gut Grinder")
- Handkerchief ("Susan Strong")
- Headphones, microphone, and Walkman ("It Came from the Nightosphere")
- Ice King's beard ("Loyalty to the King")
- Jake's snow booties ("Adventure Time," "The Chamber of Frozen Blades")
- Jake's viola ("Gut Grinder," "What Was Missing")
- Ketchup ("Conquest of Cuteness")
- Kibble, steak flavored ("Jake Suit")
- Legal pad and pencil ("Five Short Graybles")
- Margaret's music box ("Jake vs. Me-Mow ")
- Marshmallows ("Susan Strong")
- Noodles ("What Was Missing")
- Paper bag with red erasers ("Red Starved")
- Pink sweater ("Mortal Folly," "Mortal Recoil")
- Pocket knife ("Red Starved")
- Pudding and spoon ("The Duke")
- Root Sword ("Belly of the Beast," "Jake vs. Me-Mow")
- Rope, trail mix, flute, toothbrush, and water bottle ("Prisoners of Love")
- Scissors ("To Cut a Woman's Hair")
- Soul food: collard greens and country fried steak ("It Came from the Nightosphere")
- Spoon of Prosperity ("Red Starved")
- Spaghetti dinner: checkered table cloth, two plates, two forks, two wine glasses, and a globe candle ("To Cut a Woman's Hair")
- Sugar cube ("Freak City")
- Yellow sweater ("Adventure Time," "The Chamber of Frozen Blades")
- Golden dagger ("The Monster")
- Miscellaneous junk: green eyeball, three socks, purple and green potions, pink star, lizard, underpants, pouch, clear and pink blobs, flashlight, two buttons, note from Princess Bubblegum reading "Do not lose this paper -Princess Bubblegum" ("Gut Grinder"); blue eyeball, roll of tape, diamond, indiscernible junk ("Mortal Folly"); pink and blue sock, blue gem, soda can, cup, bone, blue flashlight ("Red Starved")
- Tablet-like communication device ("Reign of Gunters")
- Zip-top bag with cookies ("Red Starved")
- Walkie-Talkies ("Jake The Brick")
Finn's pack has been completely destroyed twice:
- "Gut Grinder" (pack c; first complete destruction of the pack)
- "Mortal Folly" (pack torn apart by the risen undead; although Raggedy Princess brings Finn a brand new backpack made by her and other princesses that seems to look exactly like his old one)
- Finn's pack has been damaged in three episodes. These include "Donny," in which it was scratched by a Why-Wolf; in "Gut Grinder," in which the backpack was caught on a rock, tearing it open; and in "Mortal Folly," in which the pack was torn by the risen undead.
- In "Belly of the Beast," Finn's pack has, for the first time, a strap to hold the Root Sword. Traditionally, his Gold Sword was either put into the pack or held against his back between the pack and him. The strap appears to be an addition to the pack, as it is made of a different color material than the bag and poorly stitched. The strap disappears upon entering the Monster.
- Because his pack was destroyed in "Mortal Folly," Raggedy Princess brings Finn a new pack at the start of "Mortal Recoil." This is the only known occurrence of Finn's pack's simply being replaced, rather than repaired. It is worth mentioning that this new pack appears to be weaker than Finn's old pack, as it becomes badly torn after Finn is thrown through a wall. (A similar event did no harm to the previous pack.)
- Finn's pack may have been also been destroyed in "Wizard," although it is unclear whether Finn was wearing the pack underneath his wizard robes when the meteor exploded.
- Finn's gender-swapped counterpart Fionna has the same type of pack.
- In a few of the episodes, Finn is seen using a corded telephone that is connected to the inside of the pack.
- In the MAD skit, "Malcolm in the Middle Earth," Finn's clothes and backpack colors are switched.
- A real version of Finn's backpack is available on the Spencer Gifts website.
- Finn's pack was not seen in the episodes "Is That You?" and "The Pajama War."