Legendary

 items are rare weapons featuring unique red text effects, with a, or  coloration on their item cards in Borderlands, and an  coloration in Borderlands 2, Borderlands: The Pre-Sequel, and Borderlands 3. Unlike items, legendary items can spawn at any time, can usually be acquired anywhere, and don't have any restrictions on their parts, provided generic rules are respected.

About Legendary Items

 * Each manufacturer has one (and usually exactly one) legendary weapon for each weapon type it manufactures.
 * Orange weapons with inherent elemental properties are especially strong because they provide the elemental effects with no loss of damage rating (or sometimes even an increase), unlike normal elemental accessory parts that reduce damage by up to 40% in exchange for elemental properties. However, this only applies to orange weapons that inherently possess a specific element, like the Atlas Ogre or Maliwan Hellfire. Orange weapons that do not inherently come in a specific element can occasionally be randomly generated with various elemental accessories, but these will result in a reduced base damage rating, as normal.
 * In Borderlands 2 and Borderlands: The Pre-Sequel, legendary items are more akin to pearlescent items in Borderlands - each legendary in both of those games features a unique material pattern and some have more than one predefined part.
 * All Legendary weapons can be acquired from any loot source (this is referred to as a World Drop).

Pearlescent Items
items are a cross between unique items and super-legendary items. Please see the article for more information.

List of Legendary Items (Borderlands)
There is one (and exactly one) legendary weapon per valid manufacturer-weapon type pair. This table can be sorted to display either by manufacturers or by weapon types (or by model).

Trivia

 * Most items with flavor text on it carry a reference that is either historical, based on pop culture or a quote from a well-known individual or game.