Grant Williams stayed in character in Batman costume after Celtics game, and Jayson Tatum was unamused

Celtics forward Grant Williams has a ton of interests off the court, and one of those interests is comic books. He even calls himself Batman.

Last year, Williams assigned nicknames from the Marvel universe to everyone on his team. Jaylen Brown was Black Panther. Tatum was Vision. Robert Williams was Thor. Marcus Smart was The Incredible Hulk. Payton Pritchard was Quicksilver. His coach, Ime Udoka, was Nick Fury.

His comic book-inspired nickname, however, came from the DC universe. According to Williams, his father began calling him Batman after how well he guarded Nikola Jokic.

Williams said it wasn’t just because he shut down the MVP (via MassLive):

“It was more so I’m not like the most athletic,” Williams said of the nickname. “I’m not the most incredible, but brains and then like everything else you work with, that was the Batman kind of spiel. So (my dad) joked about that.”

Williams asked if Jaylen Brown could relay the message to reporters, but Brown said he wasn’t so sure about that one.

Flash forward to this year and the day before Halloween, Williams dressed up as Batman during his postgame interview after Boston’s win against the Wizards. Using an uncharacteristically deep voice, he then answered every question as if he actually were Batman.

He told one reporter that he and his teammates “kept Boston safe” and another that they are “just as good in the lights” as they are in darkness.

The entirety of the back-and-forth was very silly and worth watching, but after about a minute into the exchange, Tatum saw what was happening and couldn’t help but interject.

He loudly asked Williams what he was doing, and everyone began to laugh:

Grant being Grant…

Tatum: Wtf are you doing!? @Grant2Will @jaytatum0 pic.twitter.com/j8WzACgP9r

— Celtics on NBC Sports Boston (@NBCSCeltics) October 31, 2022

Tatum was visibly confused when he learned about the nickname last year and he said that he would only call him Grant, “not no damn Batman.”

Ime Udoka, who was coaching Boston at the time, said he wasn’t buying it but would live with it. Brad Stevens, the head of basketball operations for the Celtics, said he refused to call Williams “Batman” as well.

Al Horford was the only teammate who seemed interested in having any fun.