The planet Terra is very similar to the world in the original Junk Jack. Terra is inhabited by real-world animals, such as cows, sheep, pigs, and chickens. The hostile mobs of Terra consist of common fictional monsters, such as zombies, skeletons, etc.. Terra is the default world that all players start in before unlocking other planets.
Terra directly translates from Latin into the word "Earth". It is obvious that Terra is the Junk Jack equivalent of Earth, due to the flora, fauna, and general geography of the planet.
 Getting to Terra
There is no need to find Portal Pieces to get to Terra. Any newly generated Adventure Mode worlds will start on Terra, and from the very beginning players are given the option to generate stand-alone worlds on Terra. After travelling to a new planet a Terra portal will automatically spawn.
- Summer Biome: A beach-themed biome with Date Palm Trees, Pristine Sand, etc... Exclusive Summer Chests containing beach-themed items as of the 2.2 Summer Update.
- Forest Biome: A typical forest, regular and Cork Oak Trees are commonly found in these areas.
- Winter Biome: Mostly consists of Spruce Trees and Ginger Plants, but are very small when generated in Adventure Mode.
- Library Biome: A castle-themed library filled with Bookshelves, Red Tabards, Red Long Carpets, and Weapon Stands which drop Iron Swords.
Iron, Gold, and Iron Archer Knight Skeletons occasionally spawn here. Found in the top-middle area of the world.
- Prison Biome: A dark prison filled with Wall Jails, Wood Guillotines, and Keychains which drop Keys.
Prison Zombies occasionally spawn here. Found in the middle-bottom area of the world.
Miner Zombies occasionally spawn here. Found in upper-middle area of the world.
- Spore Biome: A graveyard-like biome filled with Gravestones, Amaranthus, Mushroom Plants, and Purple Candleleaf plants.
Found in the bottom or bedrock layer of the world.