Colin Farrell Unrecognizable Again as the Penguin Amid Oscar Season

Colin Farrell is back in chameleon mode ... looking like his typical debonair self one day, then a villainous Batman foe the next -- BTW, at the moment, he's focused on the latter.

The Irish actor was on set Monday in Manhattan, where production was getting underway for his new HBO spinoff show, "The Penguin" ... which is all about his titular role from 2022's "The Batman" ... the first time Colin rocked this truly unrecognizable look.

Welp, he's back in character and in costume ... and once again, you would never know this was CF at first glance. The hair, makeup and prosthetics are still on point.

His appearance is essentially the same as it was in the flick, only now ... he's getting an 8-episode series that's solely focused on him and his mob boss journey in Gotham (sans Robert Pattinson's Batman, per reports). It remains to be seen if other Bat baddies will make cameos in the show ... including Barry Keoghan's Joker, who also popped up in 'TB.'

Speaking of Barry, he's in another movie with Colin that's up for a lot of Oscars right now -- "The Banshees of Inisherin" -- and the 2 of them have been hitting the town as they gear up for Sunday's big ceremony, which they're both expected to attend.

Take a look at what Colin looked like just over a week ago ... completely different from his current state on set.

No, he didn't gain a ton of weight in a matter of days -- dude's wearing a fat suit, just as he did in 'Batman.'