While Deadpool is often held up as the pinnacle of wise-cracking, fourth wall-breaking comics anti-heroes, the lesser-known DC Comics character Ambush Bug actually made his debut almost a decade before the Merc with a Mouth. Much like Wade Wilson, Ambush Bug initially appeared as a villain before ultimately deciding to become a hero (for no clear reason). But unlike the massively popular Deadpool, he never really took off with comic fans.
Ambush Bug is the alias of Irwin Schwab, though whether or not that is his real name is up in the air. He was created by Keith Giffen and Paul Kupperberg and made his first appearance in DC Comics Presents #52 in 1982. Schwab suffers from a myriad of mental problems that make it difficult for him to comprehend reality and discern the world around him. As a result of this, he has a cosmic awareness and knows that he is in a comic book. To top it off, his green skintight suit grants him teleportation and invulnerability.
Deadpool may be more famous and beloved by fans, especially after his self-titled film in 2016 and its 2018 sequel, but he didn't appear on the comics page until nine years after Ambush Bug. Wade Wilson made his debut in 1991 in New Mutants #98 by Rob Liefeld and Fabian Nicieza. He originally started off as a serious bounty hunter and mercenary. It wasn't until he received his own ongoing title in 1997 by Joe Kelly that he would become more of a satire of the anti-hero trope that became popular in comics in the 1990s. Over the years he grew in popularity, losing his satirical elements and becoming more of a straight-up comedic character, while Ambush Bug was banished to the depths of comics obscurity. Even though he came first, Ambush Bug was never really given the chance to shine by DC Comics.
Outside of a self-titled miniseries in 1985 and a sequel, Son of Ambush Bug in 1986, Ambush Bug was mostly relegated to cameo appearances in the '80s and ensuing decades. It's possible that he was ahead of his time, and that comic readers found him to be too weird and goofy. On the other hand, Marvel gave Deadpool the chance to grow a fanbase, finding most of his success by pairing him with more straight-laced characters such as Cable, Captain America or Thor. These Odd Couple team-ups allowed Wade bounce off of someone while making him more easily digestible for readers. His more straightforward humanoid design also fits right in with the time period he comes from, whereas Ambush Bug sticks out like a sore thumb.
The relative obscurity of Ambush Bug has garnered him a cult following. In recent years he's appeared as a member of the Doom Patrol and the Suicide Squad, while also "hosting" the comic series Let Them Live! Unpublished Tales from the DC Vault. If DC Comics had given him a chance to grow and flourish in the 1980s, he might have risen to a higher level of popularity. But for now he's stuck in the shadow of Deadpool, even though Ambush Bug came first.