On the morning after the Portland Expo was filled with costumed superheroes and “Star Wars” storm troopers as part of a comic book convention, a genuine larger-than-life figure took to the floor.

Taller than Andre the Giant, able to grasp a 10-foot basketball rim without leaving his feet (which are nestled in size 22 sneakers) and already beloved in Boston, Tacko Fall arrived in town early Monday morning and took part in his first practice as a member of the Maine Red Claws.

The Red Claws, of course, are the G League affiliate of the Boston Celtics, who signed the big fella after he was passed over in the June NBA draft despite his 7-foot-5 height (in bare feet), 8-foot-2 wingspan and 10-foot-3 standing reach. He tips the scales at more than 300 pounds, and moves with surprising grace and agility. In his four years at the University of Central Florida, he blocked 280 shots and set an NCAA record by making 74 percent of his field-goal attempts.

“Being 6-10 or 6-11, you don’t usually look up to people,” said John Bohannon, Maine’s tallest player from last season, after scrimmaging against Fall on Monday morning. “Just standing up next to him, I was like, ‘Damn, it’s crazy.’ He’s definitely a spectacle.”

At one point in the scrimmage, Bohannon received a pass within a foot of the basket, normally an automatic dunk for him. But he saw Tacko towering overhead and wisely kicked the ball back out to a teammate.

“Man, this is how (normal) people look at me,” Bohannon said. “I’m definitely glad he’s on my team.”

The Red Claws have a new coach, Darren Erman, with a fascinating backstory. They return fan favorite Trey Davis, who set the team single-game scoring record of 57 points in March 2018. They boast a quicksilver point guard, Tremont Waters, who grew up in Connecticut and led Louisiana State to the Sweet 16 before the Celtics drafted him 51st overall after his sophomore year.

And yet pretty much all anybody wants to talk about is Elhadji Sereigne Tacko Diop Fall, who already in his nascent professional career has heard chants of “We want Tacko!” resonating not only from TD Garden during Celtics exhibition games but from Madison Square Garden on Saturday night against the New York Knicks.

“Every game we go to feels like a home game when Tacko’s there,” Waters said. “Because everyone wants to see Tacko go in.”

Waters, who is listed at 5-foot-10, and Tacko are roommates. They’re also the two Red Claws signed to two-way contracts, meaning they spend most of their time in Maine but are allowed up to 45 days with the parent Celtics, at a pro-rated salary of the NBA minimum $898,310. Tacko’s debut against the Knicks on Saturday night, when he had a dunk and a lay-in in 21 seconds near the end of a lopsided victory, doesn’t count against his 45-day limit because G League training camps had yet to open.

At precisely 10 a.m. Monday, Tacko strolled onto the Expo floor wearing a black hoodie beneath a gray Red Claws practice jersey. He did a few around-the-basket drills with returning assistant coach Alex Barlow and a three-man offensive drill that included him launching 3-pointers (air-balled from the corner, swished from the left wing). Later came three-on-three, four-on-four and five-on-five action.

“We’re getting flooded with calls, both for season tickets and general interest in the team,” said a Red Claws spokesman, Evans Boston. “There was a massive spike when the Tacko two-way (contract) was announced.”

Boston said individual-game tickets will go on sale at 10 a.m. Friday, both online and at the team offices on Forest Avenue in Portland. To prepare for Tacko’s arrival, one team employee has been busy arranging for a California King mattress to be delivered to the two-bedroom suites the Claws provide for their players.

At 72 inches wide and 84 inches long, the mattress will require the removal of other furniture to fit it into the bedroom, but it still remains a half-foot shorter than the full-size Tacko.

“He can’t go to the mall and if he goes, he has a hundred people asking for a picture,” Waters said. “He’ll stop for every last person. I’ve never seen someone be so open and embrace it as much as he does. He’s definitely a different breed in that aspect, for sure.”

Soccer was the first sport for Tacko, who grew up in Dakar, a city of more than a million people in Senegal, the westernmost country in Africa. He came to the United States at age 16 with another Senagelese teenager hoping that basketball could pave the way for a college education and wound up at a small Christian prep school in Florida, living with a host family.

For the next seven years, until his senior year at Central Florida, Tacko didn’t see his mother. She finally got to see him play before he led Central Florida to the NCAA tournament for the first time in 15 years, beating Virginia Commonwealth before falling just short of an upset over top-seeded Duke.

He’s learning to play guitar and, as a devout Muslim, wears jersey 99 as a nod to the 99 Names of Allah. Teammates and coaches gush about his personality and work ethic. He speaks four languages: English, French, Arabic and an African dialect called Wolof.

“I’ve never experienced a winter so it’s probably going to be a shock the first few days,” Tacko said about his upcoming months in Maine. “But I’ll probably get used to it.”

As for the frenzied hype swirling around him since he began turning heads during the Celtics’ summer league season and continued with fans dressing up in taco costumes, Fall said he tries to ignore that and work on the improvement necessary to carve out a career in the NBA.

“I’ve just been trying to focus on what I have to do and not let too much of the noise on the outside affect me,” he said, “just concentrate on what I need to do, which is to get better.”