Watch Nathan Fillion's triumphant cephalopod return as Resident Alien's favorite octopus

In the Resident Alien Season 2 premiere, there are plenty of "Old Friends" the episode title could be referring to. However, one character seems like a likely candidate as the Old Friend: Nathan Fillion's restaurant octopus.

Harry Vanderspeigle (Alan Tudyk) has returned to Earth after a brief jaunt into space only to have his mind wiped upon crash-landing. With no memories to speak of, his human mind grasps for a new identity and lands on none other than Detective Lennie Briscoe of Law & Order fame. Season 1 fans will recall that Harry spent his first months on Earth binge-watching Law & Order to learn about humanity — and who amongst us hasn't wanted to embody a favorite character? However, Harry takes his fandom obsession one step further than most by becoming convinced he is Det. Briscoe.

In an attempt to jog his memory, Harry's best friend Asta Twelvetrees (Sara Tomko) — whom Harry is convinced is his prostitute informant Cosette, by the way — takes him to eat at a local sushi restaurant. At that restaurant is a fish tank, and in that fish tank lives a telepathic octopus we first met in Season 1. Fans will know from Season 1 that, actually, all octopuses are telepathic because Harry's race is descended from the octopuses that first arrived on Earth countless years ago. Most octopuses just choose not to speak to humans because, let's be honest, why would they?

"We first had the idea of the octopus because we wanted to connect Harry and Harry's people to Earth somehow. We wanted to figure out, 'Why Earth? Why does he care so much?'" series creator Chris Sheridan tells us about the origins of Fillion's octopus character. "Only to find out that the octopus is a distant relative of his. And in the process of doing research on octopuses — which people realize there's no other animal on Earth that is as alien as the octopus. Incredibly intelligent. So it worked really well and when we first were casting that octopus, my first thought was, 'Maybe Alan could do it because he's so great with voices.' It was Alan's idea, I believe, to go to Nathan because they have a history together."

Whereas Harry's speech patterns are juvenile (since he's new to this whole "human body" thing), the octopus "just speaks like a guy," as Sheridan explains. "There's no sense of alien in there. He knows stuff there's no way he could possibly know."

He also teases what's to come for Fillion's octopus in the remainder of the season. Harry and the octopus' "Odd Couple" hijinks will continue in spectacular fashion. "I will say, without spoiling anything, the way that friendship culminates this season I think is one of the funniest things we've done, in my mind, for the whole series," he says.

It's thanks to Fillion's octopus in Season 2's premiere episode that Harry gets his memories back. Conveniently, Asta also learns a little more about Harry's alien race and the octopus calls her an idiot, all of which will come into play later in the season. How will the octopus' journey continue? Keep watching new episodes of Resident Alien as they premiere on SYFY on Wednesdays at 9/8c, with next-day streaming on Peacock.