The Gremlins are the fictional and unknown reptile-like creatures who are the primary antagonists of the entire Gremlins franchise. They made their debut in the 1984 film Gremlins and then reappeared in its sequel Gremlins 2: The New Batch (1990). They are also based upon the creatures with the same name of old English folklore.
In both movies, the Gremlins have a leader that is smarter than all others. Stripe is the leader in the first movie and though the Brain Gremlin is the smartest, Mohawk is briefly the leader in the second movie (before being replaced by the smarter Brain Gremlin).
In the films, different voice actors have provided the vocal effects of the Gremlins: Bob Bergen, Peter Cullen, Mark Dodson, Bob Holt, Fred Newman, Michael Sheehan, Kirk Thatcher, Frank Welker, and Michael Winslow.
The Gremlins are nasty, vicious reptile-like creatures who originated from the Gremlins franchise. They were trapped inside of the Phantom Zone alongside their leader Stripe until the Joker came along and set everyone trapped in there free. The Gremlins joined Joker and the rest of his Uber Villains in an attempt to destroy all of Gotham City. In the end, they were trapped back inside of the Phantom Zone along with the rest of the escapees.