Tricksters are portrayed as both heroes and villains in modern film and television. Though they are thought of as villains most often. But is the Trickster evil? I don't think that is the case. While the Trickster is often the antagonist he isn't necessarily evil. Take the character Q from Star Trek: The next Generation as an example...
While he is the antagonist for several episodes of the series, he isn't truly evil. He is often just bored and looking for a way to have fun. His fun comes at the expense of his tricks and riddles. Another example of this kind of Trickster is the Great Gazoo from the Flintstones cartoon.
Gazoo often helps Fred and Barney in the series, but not without giving them some grief and playing tricks on them. He is funny yet harmless. Then there are Tricksters that are technically good, but when you examine their motives and actions you see that they are truly tricksters. The first that comes to mind is Bugs Bunny.
Bugs is considered the hero in his cartoons, but he walks a morally shaded line. He tricks and fools his nemesis much like the classic Tricksters of mythology, however, he is popularly considered the "good guy." Another of this type is The Mask.
In this film Jim Carrey is the protagonist, but he has antagonistic instincts. He robs a bank, he plays tricks on people and acts on the fringes of acceptability. Very much the same as Jack Sparrow in the Pirates of the Caribbean series of films.
After looking at some good and fringe Tricksters, we should now see how the Trickster is portrayed as the evil antagonist. The first is the minor villain, Wile E. Coyote. He rarely ever wins, but is very much a trickster.
As I continued looking at Tricksters I started to see some more evil examples. The next one I found was Jareth the Goblin King from the film Labyrinth.
Jareth is truly an evil Trickster. He uses all of the Tricksters wiles, like shape-shifting and riddles to push and prod the heroine along. It is all for his evil desires. He wants to steal a child and uses his wits to confuse and confound the heroine from ever being able to find her way to saving the child. Then I happened on the Trickster that I find to be the most evil, and the is the Joker from the Batman comics and film series.
The Joker is not only the most evil incarnation we find in film and television, but he is also the one that appears the most evil. While all forms of the Trickster have something humorous or clown-like about them, the Joker is skewed to an off-putting look.
In the end the Trickster is everywhere in popular culture. But rarely is he seen as the true evil villain. We see him in his many forms wreaking havoc on small levels like Bart Simpson and the Pink Panther. We see him as taking the form of a lesser villain like Beetlejuice and Peeves(from Harry Potter). We also see him at his most evil, in both film and religion as Satan.
While I chose a comedic picture of Satan to keep it light and fun, the trickster character of Satan is seen as the most evil of all demonic gods, and the one that provides a societal picture of true evil.