Karborg (Kerbog in the 4kids version) is the weakest type of shadow monster, the bat-like ones that fly around the castle in swarms. He is Lord Darkar's personal pet. He can be distinguished from other bats by his slightly lighter colour as well as a little pink spot on one of his "wings". Darkar can alter Karborg's form using shadow  Karborg's final form.Added by Fswe1 magic, turning him into incredibly powerful creatures. Karborg can make contact with Darkar by hanging on his arm. He has had several uses:
- In the episode "The Shadow Phoenix", Karborg informs Darkar that the Codex consists of four parts and not one, as Darkar thought.
- In the episode "The Party Crasher", Karborg is transformed into a monster called the "Gregthroat" (Liodragarus in the 4kids version) and attacks Red Fountain in order to distract everyone so that the Trix can steal the Codex.
- In the episode "The Spy in the Shadow", Karborg is sent to Alfea and takes another part of the Codex from Shadow Bloom and flies off to Darkar.
- In the episode "Face to face with the enemy", Darkar turns Karborg into another fearsome monster (Called Opticeratops in the 4kids version), which cannot be harmed by magic. It guards Darkar's throne room. It has a very large battleaxe which he uses to cause earthquakes, slash at enemies and block magical spells. He attacks the Winx but as they run off to open the Realix portal, Griffin, Faragonda and Codatorta fight him. At first he seems unbeatable, but after the women gave Codatorta superhuman strength and speed, he manages to crush the monster. Karborg attempts to fly away, but Griffin and Faragonda ultimately destroy him using the spell "Vallax Venum".