Tide Glider

The Tide Glider is a Tidal Class dragon introduced in Dragons: Rise of Berk. They later became available in School of Dragons.

Appearance
The Tide Glider is light, faded blue in color. It has two coral shaped horns and a relatively long snout. It has three small fins set on its long neck. Its wings have wavy white patterns all over and it has a large tail fin. Instead of legs, the Tide Glider has two front flippers. In Dragons: Rise of Berk, this is a very thin-bodied dragon. In School of Dragons, it has a rounder belly and also possesses two hind limbs.

Description
This graceful Tidal class drifter doesn't "swim" through the water, it dances! Its saliva is said to have healing qualities... but it is too skittish for anyone to find out.

The Tide Glider coasts along the waves peacefully, until it spots an enemy in the distance and shoots an acid ball to clear a path!

Abilities
The Tide Glider is able to shoot acid at its opponents and it serves as a useful attack and defense.

Its saliva is said to be able to heal people, making it similar to the Scauldron's venom, which can be used as an antidote for dragons that are poisoned by the Blue Oleander. This ability allows it to heal other animals, dragons and humans. Its saliva might also be in its water blast, which can be used to heal wounds by spraying them.

Tide Gliders can be inferred to be very agile and graceful as they are described to 'dance' through water instead of swimming.

Titan Wing
Source: Dragons: Rise of Berk

The main difference in adult and titan Tide Gliders is their color. A titan Tide Glider has a darker, more vibrant shade of blue and pink wing edges that have swirly patterns. They have more frills on their crown and a larger tail fin. Apart from that, they are rather similar to adult Tide Gliders.

Trivia

 * According to Rise of Berk, Tide Glider eggs can be found in Dark Deep, but when Hiccup and Fishlegs got there in Quake, Rattle and Roll, or when Fishlegs was looking at the Dragon Eye with Meatlug's colored lava, the Tide Glider wasn't seen or even mentioned. It is possible that Tide Gliders were discovered only after the events of Race to The Edge.
 * The Tide Glider is the first original dragon in Rise of Berk to appear in School of Dragons.
 * In School of Dragons, the Tide Glider sprays water. It is the third to do so, the others being the Scauldron and the Bewilderbeast. However, it is unknown if it changes the temperature of the water it fires like the others. Bubbles also form as the water is fired.
 * In Rise of Berk however, they shoot balls of acid.
 * According to this evidence, the Tide Glider can shoot both water and acid.
 * The Tide Glider's healing saliva is most likely contaminated in it's water blast as it sprays it out. This might mean that the Tide Glider fires acid balls for attack and offense/defense purposes, while it can also spray it's saliva-contaminated water for occasions when healing purposes are needed.
 * Tide Gliders bear a strong resemblance to the weedy sea-dragon.
 * While the Tide Glider has hind legs in School of Dragons, it lacks them in Rise of Berk. In School of Dragons they need legs to walk, which might explain the difference.
 * The Tide Glider was the first dragon to be released in School of Dragons in 2015.