Source: Extracted directly from torvalds/linux git repository + historical RC-level codenames.
| Kernel Version / RC Tag | Official Codename | Context / Backstory |
|---|---|---|
| 2.6.1 | (none) | Pre-codename era |
| 2.6.2 – 2.6.4 | Feisty Dunnart | Early 2.6 codename |
| 2.6.5 – 2.6.9 | Zonked Quokka | "Quokka" appears here (RC-era) |
| 2.6.10-rc1 – 2.6.13 | Woozy Numbat | Australian marsupial theme |
| 2.6.14-rc1 – 2.6.15-rc5 | Affluent Albatross | Bird theme |
| 2.6.15-rc6 – 2.6.17-rc4 | Sliding Snow Leopard | Big cat reference |
| 2.6.17-rc5 | Lordi Rules | Eurovision band reference (Lordi) |
| 2.6.17-rc6 – 2.6.18-rc7 | Crazed Snow-Weasel | Weasel theme |
| 2.6.18 – 2.6.20-rc1 | Avast! A bilge rat! | Pirate theme |
| 2.6.20-rc2 – 2.6.21-rc3 | Homicidal Dwarf Hamster | Humorous rodent theme |
| 2.6.21-rc4 – 2.6.22-rc2 | Nocturnal Monster Puppy | Dog theme |
| 2.6.22-rc3 – 2.6.22-rc4 | Jeff Thinks I Should Change This, But To What? | Meta / in-joke |
| 2.6.22-rc5 – 2.6.23-rc3 | Holy Dancing Manatees, Batman! | Pop-culture reference |
| 2.6.23-rc4 – 2.6.23-rc6 | Pink Farting Weasel | Absurdist weasel |
| 2.6.23-rc7 – 2.6.25-rc1 | Arr Matey! A Hairy Bilge Rat! | Pirate theme |
| 2.6.25-rc2 – 2.6.26-rc5 | Funky Weasel is Jiggy wit it | Funk/weasel combo |
| 2.6.26-rc6 – 2.6.27 | Rotary Wombat | Australian animal |
| 2.6.28-rc1 – 2.6.28-rc6 | Killer Bat of Doom | Dark bat theme |
| 2.6.28-rc7 – 2.6.29-rc8 | Erotic Pickled Herring | Absurdist food reference |
| 2.6.29 – 2.6.30-rc3 | Temporary Tasmanian Devil | Tasmanian Devil |
| 2.6.30-rc4 – 2.6.30-rc6 | Vindictive Armadillo | Armadillo theme |
| 2.6.30-rc7 – 2.6.39 | Man-Eating Seals of Antiquity | Mythical seal theme |
| 3.0 | Sneaky Weasel | Transition to 3.x |
| 3.5 | Saber-toothed Squirrel | Prehistoric animal |
| 3.10 | Unicycling Gorilla | Circus animal |
| 3.11 | Linux for Workgroups | Windows 3.11 homage |
| 3.12–3.13 | One Giant Leap for Frogkind | Apollo 11 pun |
| 3.14–3.17 | Shuffling Zombie Juror | Zombie/legal humor |
| 3.18–3.19 | Diseased Newt | Disease theme |
| 4.0 | Hurr durr I'ma sheep | Meme sheep |
| 4.5 | Blurry Fish Butt | Fish absurdity |
| 4.14–4.16 | Fearless Coyote | Road Runner reference |
| 4.17–4.18 | Merciless Moray | Moray eel |
| 4.19 | "People's Front" | Monty Python reference |
| 4.20 | Shy Crocodile | Shy animal |
| 5.0 | Shy Crocodile | Same cycle |
| 5.5–5.10 | Kleptomaniac Octopus | Kleptomaniac octopus |
| 5.15 | Trick or Treat | Halloween |
| 5.16 | Gobble Gobble | Thanksgiving |
| 5.17–5.19 | Superb Owl | Super Bowl pun |
| 6.0–6.9 | Hurr durr I'ma ninja sloth | Ninja sloth meme |
| 6.10–7.1-rc8 | Baby Opossum Posse | Carried into 7.x |
Notes:
- Many early 2.6 names only existed in release candidates and changed frequently.
- "Zonked Quokka" is the origin of the "Quokka" reference.
- Current development (7.1-rc8) still uses Baby Opossum Posse.
- "Quokka" does not appear in modern kernels.