Dolphin

The Dolphins are animals which appear in Season 5 and 7.

Overview
They are aquatic animals who feed on a variety of seafood (e.g., fish, squid, shrimps, jellyfish and octopuses) which makes them carnivores. These animals are social creatures and travel in pods. They exist in various waters around the world in which temperatures are either a mixture of cold and warm, or warm.

Appearance
These dolphins are lavender blue with white underbellies. They "[measure] less than 3 meters (10 feet) in length, and have spindle-shaped bodies, beak-like snouts (rostrums), and simple needle-like teeth."

Season 5
The dolphins first appeared saving David from drowning. They then warn Phylla about Tritannus and Icy's attack on Paradise Bay.

Season 7
The dolphins spend time with the Winx, Specialists, and Nex. One dolphin joins in on Sky and Nex's friendly surf competition and beats them both. The Winx (except for Stella who is sunbathing) rode on the dolphins.

The Mystery of the Abyss
The dolphins do not appear in the movie but their sonar abilities (echolocation) are referenced and used by Musa and Tecna to find a way out of the Coral Barrier; Tritannus trapped them in there as revenge for his imprisonment in Oblivion.

Season 4
On a beach at Blue Bay, a dead dolphin in a net is discovered by the Winx in Issue 76: Revenge of the Sea. Seeing this brings Roxy to tears as she explains the dolphin must have been suffocated to death by the net. Tecna senses something off and wants to check it. The girls fly over the ocean and see five large vessels aiming at one man on a jet ski. The vessels are trying to force him onto the shore and one of them knocks the man off his jet ski. The man tries hard to avoid sharp rocks near him. The Winx proceed to save him but Roxy stops them and calls upon dolphins as they are much quicker in the water.

The man is saved by the dolphins who bring him ashore. The man expresses excitement and gratitude to the dolphins for saving him. Roxy also thanks them and bids them well as the dolphins return to the sea. This man is Helbert, a former Red Fountain student who is working on project to save the environment. Helbert was the person the Winx were sent to assist in place of the specialists. He also explains what is happening. Samuel Morgan and his crew have been irresponsibly fishing, using nets that capture any and all sea life. The sea creatures remain trapped in the nets and die as a result. This was what happened to the dead dolphin found ashore.

Samuel's irresponsibility had angered the ocean enough and made its wrath known. Samuel and Captain Grog are agitated and fail to see the reason for the ocean's wrath. The ocean sends whales, the largest of all creatures, to barricade Samuel's vessels. The whales eventually knock over all the vessels, forcing the crew underwater. The dolphins are called again by Roxy to bring all of them to shore. Such actions witnessed by the crew gave them the courage to stop working for Samuel. Bloom however, explains that they should not stop fishing but rather learn to fish responsibly.

Season 5
In Issue 112: The Trix's Trap, dolphins are seen in Gardenia's newest Marine Park. Their appearance bring excitement to a little boy who asks about them and other species belonging to the infraorder Cetacea.

Trivia

 * Dolphins are popular for "their grace, intelligence, playfulness, and friendliness to humans" but are wild animals that must be treated with respect and caution, and to not feed them . There are reports of humans being bit and dragged into the water by dolphins who have grown accustomed to being fed by humans, seeing them as an easy access to food.