People can't unsee who Jake Gyllenhaal looks like as he presents SNL

Jake Gyllenhaal has taken to the stage to host Saturday Night Live, and people all seem to be drawing attention to one aspect of his appearance in particular.

The Road House star rounded out the show's 49th season, but it wasn't Gyllenhaal's humor that has people talking, more his outfit which is making the rounds online.

When Gyllenhaal introduced the show he was wearing a fairly muted outfit.

This consisted of a pair of khaki trousers and a white shirt, which was extremely oversized, and was very loosely tucked in.

It might not seem like a particularly extraordinary set of garments, but believe it or not it still caught people's attention.

Why are people talking about it quite so much?

Well, if you're a fan of comedy cartoon intended for adults but watched by people probably a bit too young for them, then you may have already guessed something from the description of the outfit.

So just to reiterate, it was a large baggy white shirt loosely tucked into a pair of plain green trousers.

Did you guess it?

Jake Gyllenhaal in the opening to Saturday Night Live. (NBC)

Yes that's right, it's Stan Smith from American Dad!

Not really, it is, of course, Peter Griffin from Family Guy, the man who makes Homer Simpson look like an attentive and competent father.

People took to the comments to share their views on the outfit.

One wrote: "Why is he dressed like a yassified Peter Griffin", while another observed: "He’s dressed like Peter Griffin."

A third was wondering why they chose that outfit, asking: "Why they got him up there dressed like Peter Griffin?"

Another joked that this could be a subtle nod to a future role for Gyllenhaal, writing: "Jake to play Peter Griffin in new upcoming family guy movie."

Gyllenhaal showed off his vocal abilities. (NBC)

The season finale featured skits involving a biscuit-coveting father, Scooby-Doo and the gang, and James Austin Johnson as Donald Trump.

And no before you ask, it wasn't Donald Trump who was really under that mask.

The former president made another return to the sketch show, with announcer for the cold-open saying he would be giving a statement from his new home - 'the barricades outside a Manhattan courthouse'.

Gyllenhaal delivered the opening monologue, showing off his singing voice, but questioning why producers couldn't wait one episode for him to inaugurate the show's 50th anniversary series.

A later skit saw Gyllenhaal donning a uniform and taking on the role of the head of the NYPD urging people to 'stop punching character actors in the face' in the wake of an assault on Steve Buscemi.