Ever since his introduction in December of 1980, Deathstroke the Terminator, a.k.a. Slade Wilson, has been one of the Teen Titans' fiercest foes. He has the physicality and intellect to continually be a threat to the team, as seen in the comics and shows. Despite how iconic Deathstroke is and how deep his connection to the team is, the Teen Titans cartoon drastically changes almost everything about him. The cartoon is notably more kid-friendly when compared to both the source material and other contemporary superhero cartoons, leading to Slade's moniker Deathstroke never being used in the show.
No Longer Deathstroke
Since the Teen Titans cartoon is aimed at younger viewers, it arguably makes sense that the name Deathstroke was problematic. The subtitle of Terminator was suggested by producer Glen Murakami, but this was also shot down by the higher ups. Without any other real option besides coming up with a completely new name, the showrunners decided to have the villain be known by his first name, Slade.
This name is treated as his supervillain alter ego, and his last name Wilson, as well as anything else that would humanize the character, is glossed over. This is par for the course for the series, which never so much as gives the heroes secret identities or lives outside of being Titans.
Despite this, the name Deathstroke is referenced in the tie-in comic book. It's also worth mentioning that this comic book, Teen Titans Go! -- unrelated to the later spinoff cartoon -- features many of the elements the show either glosses over or ignores. These include Cyborg's romantic relationship to Sarah Simms, as well as the presence of Donna Troy as Wonder Girl.
A Kid-Friendly Teen Titans
Slade's name isn't the only thing censored and watered down about the character. In the New Teen Titans comics, Deathstroke is a mercenary with a strict code of honor. His feud with the Titans is strong, but it's based on revenge and his standards of never failing to fulfill a contract. In fact, he eventually becomes a begrudging ally of the Titans, turning into an anti-hero similar to Marvel's Punisher.
However, in the show, he's a generic villain bent on world domination for no particular reason, lacking any and all of the depth from the comics. His relationship with his children, such as Jericho, is untouched in the show, and the character is far more mysterious than he is interesting. He also has a mainly unexplained fascination with Robin, attempting to convince the Boy Wonder throughout the series to become his apprentice.
Brother Blood is another victim of this watered down material, going from a cult-leader to an evil headmaster. Despite Deathstroke being such an inflammatory name for the cartoon, characters like Brother Blood and Killer Moth retain their original monikers. Furthermore, the demonic Trigon is perhaps the only major Teen Titans villain to be accurately portrayed.
Outside of the even more comedic and childish spinoff Teen Titans Go!, all proceeding adaptations of Slade Wilson would use the Deathstroke name and be far more accurate to his comic book roots. For as dark and sometimes inaccurate as the Arrowverse and DC Universe's Titans are, at least they actually use one of the villains' moniker.