CLEVELAND, Ohio – Terry Rozier, the Shaker Heights High School grad now running the point for the Boston Celtics, is scary good.A backup, he stepped in for injured star point guard Kyrie Irving (remember that guy?) and helped Boston dominate despite missing its two biggest stars in Irving and Gordon Hayward.When you watch the Cavaliers take on the Celtics in Game One of the Eastern Conference Finals in Boston Sunday, you are likely to see fans, maybe even players on the bench, sporting “Scary Terry” T-shirts.It uses the name of a character on the Adult Swim animated TV series, “Rick and Morty.” And it’s a caricature of Terry wearing a “Scream” mask. There are a number of versions. The whole “Scary Terry” thing has gone viral in Boston.And it was made in Cleveland.Here’s the story:Rozier is represented by Mayfield Heights-based sports agency Verus Management Team, which has about two dozen clients, six of whom play now in the NBA. The firm’s marketing guy, Clevelander David Mariotti, is all over social media looking to promote clients, the biggest of whom is Rozier.When Barstool Sports podcast host Coley Mick slapped the “Scary Terry” nickname on Rozier, and Rozier loved it, Mariotti sprung into action. He noticed that the name was catching fire on Twitter.Mariotti reached out to his friend, Cleveland artist Glen Infante, who owns the iLTHY clothing brand. Infante drew up a cartoon caricature of Rozier’s body with a Jason mask from the Friday the 13th Movie. But Terry preferred the “Scream” mask based on the Edvard Munch painting. (The scream mask is among his many tattoos and “Scream” is his favorite horror flick.) Infante made the change.Just before All-Star Weekend in February, Rozier wore the shirt. And “Scary Terry” started to take off. Now he’s got “Scary Terry” shoes, too.”Boston loves it. They’re embracing it,” said Mariotti, who got some help in the marketing effort from Aaron Eanes and A&A Management Group.It helps that Rozier is putting a fright into his opponents on the court and seems to be a master marketer off the court and on social media.