- Main article: Maxwell
- Main article: Lily (character)
- Main article: Edgar and Julie
Maxwell's parents were also adventurers, before they settled down and had kids. Each child was given a magical item that Maxwell's parents had gotten from their travels. They were the ones who gave Maxwell his notepad
List of Brothers
- Artie (found in The Virgule Gallery)
- Bruiser (found in Payper N. Penitentiary)
- Bubbles (found in Alliteration Abyss)
- Buzz (found in Kana Craters)
- Chase (found in Abjad Dunes)
- Chilly (found in Abian Sea Front)
- Clark (found in Capital City)
- Dale (found in Tilde Reef)
- Duce (found in Hyphen Heights)
- Edwin (found in Edwin's Farm)
- Flurry (found in Pilcrow Peaks)
- Flux (found in Hyphen Heights)
- Glum (found in Alliteration Abyss)
- Gorge (found in The Under Line)
- Guy (found in Ampersand Beach)
- Hector (found in Underscore Mine)
- Jack (found in The Metaforest)
- Kenpo (found in St. Asterisk)
- Larp (found in Sir Guillemet's Castle)
- Leon (found in Vowelcano)
- Ludwig (found in Palindromeda)
- Milo (found in the Camelcase Oasis)
- Mix (found in Grave Manor)
- Moury (found in Storybook Keep)
- Mox (found in Grave Manor)
- Patches (found in the Metaforest)
- Poindexter (found in Inkwell High)
- Razer (found in Majuscule Grotto)
- Rex (found in The Saurus Park)
- Scratch (found in Bullet Point Bayou)
- Serenity (found in The Metaforest)
- Shadow (found in Sir Guillemet's Castle)
- Stunt (found in Payper Plains)
- Tanc (found in Dusty Brush Canyon)
- Tempo (found in Capital City Runoff)
- Tiberius (found in Tomb of Onomatopoeia)
- Tiny (found in Ampersand Beach)
- Tony (found in Dusty Brush Canyon)
- Tots (found in Storybook Keep)
- Yarrr (found in The Listy Colon)
- Edgar, Julie, and Lily can be spawned using "@" objects, cloning machine or teleporter.
- Edgar and Julie had 42 children, which is the Answer to the Ultimate Question of Life, The Universe, and Everything in Douglas Adams' The Hitchhiker's Guide to the Galaxy series.
- All of Maxwell's brothers can be spawned with the notebook.
- Mix and Mox are the only brothers that the player can unlock at the same time.
- Most of the areas have either 1 or 2 of Maxwell's brothers.
- Lily is unlockable if the player has all 60 Starites.
- Also available as avatars in Scribblenauts Unlimited are Edgar and Julie. The player can get them by collecting every starite in the game.
- Brothers can be spawned in Unmasked, but can only be played as when created in the Avatar Creator.
- Buzz (found in Kana Craters) is based off Buzz Lightyear from the Toy Story movie series.