Glide is an ability that allows you fly. It has levels 1 to 5 with 5 as the strongest and 1 as the weakest. The better Jump level you have, the higher you will go and you can stay in the air longer. A good trick for getting really high (this only works during Creature Stage) is to go to a Spice Geyser or Volcano and it will shoot you far up into the air. Glide is replaced by Hover if the Glider Pack is added to a creature as a Captain accessory.
Glide is useful for killing an Epic creature using a method known as kiting, where you fly around the epic and spit at it. It is also one of the most useful abilities in the game, good for getting around quickly, escaping battles and especially Epic creatures, and simply flying right over the nests of enemy creatures who would otherwise attack you. Also you can earn the Flight of the Bumblebee achievement for flying over 200 meters without touching the ground.
Glide can often be used to escape otherwise certain death, making it extremely useful when fighting powerful nests or being ambushed and overwhelmed by multiple hostile species. Many creatures stop chasing when the player takes off.
The best kind of foot for flying creatures is the velociraptor foot. Despite jump being level 4, the speed is level 5. This allows your creature, with a running start, to fly the fastest for a longer period of time than the Toad foot. If you want a bird-like creature to fly well with these raptor feet, extend the raptor foot toes and shrink the claws. This gives the raptor foot the appearance of being bird feet.
This is unknown if it is a glitch/bug or not, but if you use the mating call when gliding, you can immediately glide again (by pressing space/clicking the button)