Season 1
- Ghouls: The ghouls assisted Knut when he was trying to steal Stella's scepter. The are quite small, a maroon-red type colour, has yelow eyes and they can stand have four legs which two of can act as arms. The also have claws.
- Ogre: They are giant yellow beasts, they can wear clothes if desired and have a good sense of smell, not to mention that they can talk. They can be as compassionate as regular people denoting their high-level of intelligence. The only ogre seen in the series is Knut.
- Hunting Troll: As the name suggests, they are good at hunting, especially with there noses and once a troll picks up a scent, he never loses it (Except if the prey leaves the planet, but once it returns, the scent is back.). This is shown when he was tracking Bloom by using a cloth from her pant cuff. They are large, ugly, usually blue and isn't exactly very smart. They are savage creatures with nipple rings and greasy hear.
- Bingledip: A creature mentioned to be in the Redfountain stables.
- Puncture Beetle: This creature is commonly seen in the realm of Magix
- Cloudtower Spider Monsters: Spider monsters that come forth in large numbers. They attacked the Winx while they were retriving Stella's stolen scepter. Its natural enemy is the Spider Eater.
- Spider Eater: A beautiful creature summoned by Flora to take care of the Cloudtower spiders. It is a huge furry beast with four legs and a unusually long tongue.
- Cretan Minotaur: A four-armed Minotaur created by the Trix to reek havoc and spread panic while they were searching for the Dragon Fire in Alfea. It is a big, heavy creature who has a musky odour, has huge horns and has red and blue fur.
- Island Turtle: Also the Monster of Black Island. It resides in the Black Mud Swamp, near the Junior League (The Water Nymps). The Wendigo Willow, atop its shell, caused the Island Turtle to sleepwalk for ages. It has a huge shell which he kept retreating to. It also has the Zelith plant, wich the Junior League use to manufacture the air bubbles they live in. It has a big shell with lots of trees that grow in a circle around the leader tree. It's also the habitat of many birds, mostly white doves.
- Wendigo Willow: It is a parasitic tree that lives on top of an Island Turtle's shell. It emits sleeping gas. It absorbs all of the turtle's nutrients and threathen the inhabitins near the Island Turtle. It was removed by the Winx. It is red with giant tentacles which the tree use as an offense.
- Water Nymphs: They are tiny aquatic fairy-like creatures. They live in air bubbles under the leave of a water lily, which is made of the plant called Zelith. They were endangered because they couldn't obtain enough leaves. After the winx save them, Flora used her Rapid Growth Formula to multiply the number of leaves. The nymphs were so greatful that they gave Flora a Cheerful Gladiolus.
- Craven: A crow/raven used by the Trix for aerial renaissance missions. It looks much like a crow, with red or yellow eyes
- The Army of Decay/Darkness: This army can be called forth and controlled by whosoever wields the Dragon Fire (This refering to the Trix). When the creater of the army is defeated, the army will also be inevitably destroyed. It is formed out of slimy little insects. The's critters can form three types of beasts. The first is a large monster with red eyes, tentacles coming out of its mouth, gaint claws, thin legs and spikes on its back. The second is a huge, headless beast with giant fists and a rock-like body. The third and final are winged-beasts, or rather flying rays (manta rays/sting rays) that have sharp teeth.
- Snow Monster: It is a huge beast that resided on the icy Sparks (Domino). It is furry, has big tusks and has ice spikes on its back. Stella, Flora, Musa and Tecna defeated the beast.
- Ice Crabs: They are deadly crab-entities made of ice. They have sharp claws. The are blue-white with narrow eyes of the same colour.
- Beetle Roaches: They are spider-like creatures who feeds of garbage, especially the one at the Cloudtower castle. The have cringing faces and thier mother is pink, rather than green and is also bigger. When she retreats, the others will retreat with her.
- Arachni cam: It's a spider-like creature with an eyeball on its back used by the Trix. it can project images in the eye and the lids can open and close at will. This eyeball is used as a camera for surveillance or to spy on other creatures.
Season 2
- Kerbog: Darkar's favorite shadow minion and his loyal servant. Darkar uses him for spy missions, as well as turn him into several powerful mythical beasts to further his own selfish needs. It is entirley black and has narrow eyes and small to medium wings.
- Hell mastiff: One of lord Darkar's many minions.
- Spit monster: Another of lord Darkar's minions.
- Brute monster: Yet again one of lord Darkar's minions.
- Guard/Rock worm: A gigantic worm that lives in Downland and serves as it's protector and guardian. It can munch his way through any type of matter, specifically rock. It is a yellow type colour and has spikes.
- Cave Spirits: Never-before-seen spirits said to live in the old caves of Downland and, once they get angry, they send out monsters.
- Magi-beavers: Beavers which come from Magix. If two, or even one, is disturbed while they are doing something, they will chew up a tree there disturbers in and knock it down, like they did to Sky and Brandon.
- Leodragerus: A dragon/ lion-like beast said to be extinct. Lord Darkar transformed Kerbog into a Leodragerus to serve as a distraction while the Trix search for the Codex. It is immune to magic, but when Helia tied him with his laser string glove, it is revealed that tying the beast will cause him to fight his own strength. The specialists defeated him. Once defeated, it reverted back to Kerbog.
- The Angel of Doom: A mythical and legendary creature. He isolates strong groups, and later drain there powers. He act first as a hero to gain poeple's trust, and once the three ancient planets align, he reverals his true form and identity. Tecna suspected that Professor Avalon (Darkar's shadow spy) could be this diety of darkness, but is proven wrong in the end.
- Unnamed Shapeshifting monster: This creature lives in the Grim Realm. He is a shapeshifting creature, who starts out as a wolf-like monster with a rightside-up head and a upside-down body, he then gets four arms, claws and turns into a flyng bug-like beast. It appeared in the episode were the winx were in the simulator. Darcy hypnotized the specialist-in-trainig, Jared, to set a trap. It is immune to magic and the Winx defeated it with convergence.
Season 3
- Ice snakes: Powerful white snakes that breathe Ice and lives in the Omega Dimension.
- Mer-Monsters: Mermaids that were changed into monsters by Baltor and the Trix when they broke out if the omega dimension. There eyes change colour and there faces get more hidious.
- Kraken: A Kraken which lives in the underwater mermaid prison on Andros/Tides. It is a squid-like monster.
- Storm Harpy: A flock of it was created by Stormy with the power Baltor gave her. She created them while the Winx was on Linphea, Flora's home realm. They can conjure up storms. They have scary faces and huge wings, which help them push by the wind.
- Giant Ladybug: These ladybugs resides on Linphea. Where tecnology were forbidden, they used these to move around. They are intelligent as they can obey commands. They have a red body with black spots, black beady eyes and they can fly.