The Cameroonian is noticeably more defined in the photo from UFC 260 in March compared to a press conference shot from UFC 220 in 2018.
He captioned the post: “Same weight, but different shape,” and then accompanied it with the muscle emoji.
The 34-year-old – weighing in at 263lbs – is in his first title reign in the heavyweight division, having defeated former champion Stipe Miocic in a rematch at UFC 260.
Ngannou defeated his American rival by KO in the second round with a straight shot to the jaw, having lost the first fight to Miocic at UFC 220 via unanimous decision.
He is unbeaten in his last five fights, including three knockouts in under a minute, bringing his full win-loss record to 16-3, with an impressive 12 KOs.
Ngannou’s first title defence is a cause of debate, however, between the fighter and UFC president Dana White.
Speaking to TMZ Sports, the champion declared his preference to be former light heavyweight champion Jon Jones, who relinquished that title last year and wants to step up to heavyweight.
White, however, appeared to pour cold water on that suggestion at UFC 263’s post-fight press conference.
“Derrick Lewis is getting that fight. It’s his fight. And Jon Jones, hopefully by then, will be ready for the winner,” he told reporters.
Lewis was the last man to beat Ngannou back in 2018, so will strongly argue his case for a title shot.
On that night at UFC 226, Lewis defeated Ngannou via unanimous decision, but has since suffered two defeats at the hands of Daniel Cormier and Junior dos Santos.
He has, though, won his last four fights, two via decision and two via stoppage.