The adolescent Demogorgons in season 2 are called Demodogs. The nickname combines “Demo,” from Demogorgon, with “dogs,” reflecting their four-legged, canine-like appearance and behavior.
Dustin Henderson helps popularize the term after discovering a young creature he briefly names D'Artagnan, or Dart. As Dart grows, Dustin and the other teenagers realize that it belongs to the same species or life cycle as the larger Demogorgon seen in season 1.
The creatures are not the same as demobats, which are winged predators introduced in season 4. They are also distinct from the Mind Flayer, the enormous shadow entity controlling the hive mind. In season 2, the Demodogs spread through tunnels beneath Hawkins and attack the laboratory after the Mind Flayer's influence expands.
Their connection to the hive mind becomes crucial: when Eleven closes the gate beneath Hawkins Lab, the Demodogs lose that link and die. “Demodogs” is therefore the established in-universe nickname, not merely a fan label.