Kumail Nanjiani Got Jacked for 'Eternals,' Keeps It Real on Process

Kumail Nanjiani looks like a new man after months and months of training and a strict nutrition regiment, which he says was no walk in the park ... for him or his wife.

The actor -- most famous for scrawny physique in "Silicon Valley" and "The Big Sick" -- posted two shirtless photos showing his now-ripped torso, and he's clearly been working out. He's got a six pack, a toned chest and super veiny arms now. Perfect for his new role in Marvel's upcoming "Eternals" movie -- in which he plays one of the superheroes.

Kumail writes, "I never thought I’d be one of those people who would post a thirsty shirtless, but I’ve worked way too hard for way too long so here we are." He went on to say he wanted to transform himself after being cast in the "Eternals" flick, adding, "I would not have been able to do this if I didn’t have a full year with the best trainers and nutritionists paid for by the biggest studio in the world." That would be Disney, of course ... also Marvel.

The guy also kept it real about the process, copping to the fact that he gets why he never looked like this before ... it's a ton of work, and requires Mickey-like resources to maintain.

Kumail went on to shout out a bunch of trainers and nutritionists who helped him along his journey ... and also his wife for putting up with his endless bitching about training and dieting.

Angelina Jolie, Richard Madden, Salma Hayek and a ton of other A-listers have also been announced as cast members for the new hero saga. Looks like it's shaping up well so far.