Kobolds have been described in various ways in various sources throughout various editions. They have been frequently described as hairless, and with red skin, and many sources describe them as somewhat reptilian, or somewhat dog-like. In more recent editions, they are more explicitly reptilian, often with a close relationship to dragons.
Kobolds are essentially self-interested cowards, with no concept of loyalty or trust, and often with a giant chip on their shoulder. They rarely fight fair: only overwhelming numbers are considered "enough," and they use traps, ambushes, and poisons to secure a victory at any cost.
Kobolds and gnomes share a passionate hatred of each other, as both favor tricks and tactics when fighting, rather than direct assault.
- Urd (2e Monstrous Compendium): A flying version of the kobold with mottled yellow-red skin and bat-like wings. They attack by dropping rocks, and have shamans that can speak with bats.
- Environmental and Elemental Variants (3e Unearthed Arcana): Aquatic, arctic, and jungle kobolds, as well as the elemental earth kobold, are described as racial variants, with adaptations to the environment or a slight elemental nature.
- OD&D: Kobolds appeared in the White Box as a monster "related to goblins," but with less HP. They have Light Sensitivity.
- 1e: Kobolds appeared in the Monster Manual.
- D&D: Kobolds appeared first in the Basic Set. Here, they are described as dog-like, but with scaly skin.
- 2e: Kobolds appeared in the first Monstrous Compendium, along with the Urd, a flying version.
- 3e: Kobolds appeared first in the Monster Manual. Here, they are explicitly reptilian in nature, and linked to dragons.
- 4e: Kobolds appeared in the first Monster Manual, and retain their draconic and reptilian features.