The champ joined Mojo Muhtadi on the  "TMZ Sports" TV show (airs nightly on FS1) ... and talked about his long-term goals now that he climbed the mountain in WWE and secured a world title.

"I need more, I'm not complacent," Priest said. "I'm the world heavyweight champ, but now what can I do? Can I be one of the greatest champions? Can I defeat every major Superstar, can I main event and continuously belong in that spot? Those are the things that matter to me now. Can I build a resume that can be Hall of Fame worthy?"

Priest is well on his way to making his case for a spot in the HOF -- Since signing with the company in 2018, he has won the NXT North American Championship, the United States championship, and both the Undisputed Tag Team Championships ... and, more recently, the world heavyweight championship back at WrestleMania XL.

While the 41-year-old has been champ for over 100 days ... he arguably has his biggest challenge to date when he steps into the ring with Gunther this Saturday at Summer Slam. Priest said he's excited to go up against one of the best wrestlers in the world, describing him as the "perfect hybrid between old school new school."

"I get to get pushed and see what I can do," he said. "Those are always extra exciting for me. This is something that has some steam behind it. We've been going at it for a few weeks. I think there's a lot of hype surrounding this match, and I'm excited, man.