Although Alan Tudyk's primary role in Resident Alien cast, Tudyk has led the sci-fi dramedy since it began back in 2021. His face has become so wrapped up in the narrative that it would be impractical and a little silly to continue the show without him. While the project is an adaptation of a comic book series by Peter Hogan, the live-action branch of the Resident Alien franchise is built around Tudyk's irreverent acting style.

Two of Tudyk's characters have been ubiquitous since the show's inception. However, his third role only manifests at the Resident Alien season 4.

Alan Tudyk Plays Resident Alien's Main Character

Harry Vanderspeigle can appear as human and in his natural alien form

Tudyk has played the show's protagonist in every episode to date. Harry Vanderspeigle's real name is not possible for humans to pronounce due to the complex nature of his species' native tongue. As a result, he's adopted a human moniker so that his human friends (and enemies) can address him. The name of Harry's true species also has yet to be revealed, but he has appeared in his natural alien form on many occasions. Harry's quirky demeanor makes him stand out to the viewers as an extraterrestrial, although very few characters seem to suspect anything until they're told.

Harry's arc began with him quietly playing the story's bad guy. His ultimate goal was to destroy the Earth. Fortunately, the longer he spent on the planet, the greater affinity he gained for the native species and their customs.

Harry has the ability to appear physically human, but there are select characters who can see through his disguise. The ability comes from a rare genetic mutation, which is present in Resident Alien characters such as Judah Prehn's Max Hawthorne, and Terry O'Quinn's Peter "The Alien Tracker" Bach. When one of these special characters is sharing a scene with Harry, Tudyk's entire head is encased in alien prosthetics to the perception that his disguise is ineffective during that time.

Harry's body remains largely humanoid when being viewed by Max or Peter, but his true form is very different.

Harry's arc began with him quietly playing the story's bad guy. His ultimate goal was to destroy the Earth. Fortunately, the longer he spent on the planet, the greater affinity he gained for the native species and their customs. Now, he actively saves his new homeworld on an ongoing basis. His character has grown a lot throughout Resident Alien's run, making him an incredibly compelling protagonist. Tudyk's performance as Harry brilliantly sells the illusion of an alien who's not great at blending in, but somehow manages to do so.

The Real Harry Vanderspeigle Is Also Played By Alan Tudyk

Resident Alien's main character killed his human counterpart before the show began

The original Dr. Harry Vanderspeigle is shown only through flashbacks and hallucinations. When the alien Harry first landed on Earth, he murdered the human Harry and took his form, name, and cabin by the lake on the outskirts of Patience, Colorado. Because Dr. Vanderspeigle was such a loner, the people of Patience had very little reference regarding what would count as normal behavior from the man - which served the alien who took his life very well indeed. The new Harry was able to integrate and serve as the town's doctor without rousing suspicion, even if he originally resisted the position.

The interactions between both Harrys were incredibly limited, as the human version was killed very soon after their first encounter.

The real Harry is very dissimilar to the alien that replaced him. Tudyk's performance as the original Dr. Vanderspeigle proves his versatility as an actor. The interactions between both Harrys were incredibly limited, as the human version was killed very soon after their first encounter. So, Harry's hallucinations where he speaks to his victim are largely an extrapolation of what the show's main character thinks Dr. Vanderspeigle would have been like. Still, it's fun to see Tudyk play such a vastly different role in the same show.

The alien Harry has run into very few obstacles after stealing Dr. Vanderspeigle's identity. The two main problems he's had to solve are when the real Harry's daughter showed up, and also when it turned out the original Dr. Vanderspeigle was responsible for the murder that was at the heart of Resident Alien season 1's story. This Alan Tudyk character could technically appear again, as none of his scenes are in the present day anyway. On the other hand, Resident Alien season 4 would appear to be heading toward much grander plots.

The Mantid Took Harry's Form In The Resident Alien Season 3 Finale

Tudyk's third Resident Alien character calls for a unique approach

Greys' Star Wars-inspired moon ship, while the nefarious insectoid returned to Earth, masquerading as Harry. From that moment, the "Harry" that had made it back to Patience was actually the Mantid. So, Tudyk was playing - and will likely have to play again - an alien, pretending to be an alien, who was pretending to be human.

Like the show's main character, the Mantid's human disguise isn't absolute.

Like the show's main character, the Mantid's human disguise isn't absolute. If someone carries the mutated gene that allows them to see Harry's true form, then they can see the Mantid's real face. This is proven at the end of "Homecoming" when Max tries to apologize to Harry and is instead faced with a terrifying visage that Sahar appears incapable of seeing. The Mantid will be a very different kind of villain for Tudyk than either of the Harry Vanderspeigles have been, as he's already shown he's willing and able to kill indiscriminately.

Tudyk Technically Has A Fourth Resident Alien Character

Goliath was an alternate version of Harry

Resident Alien season 2's story became very high-concept for a while when it was discovered that the character of Goliath was actually just the show's main character from an alternate future. Goliath is portrayed by Alan Tudyk when in his alien form. However, Goliath's human appearance belongs to actor David Bianchi. Goliath's most prominent appearance comes in Resident Alien season 2, episode 12, "The Alien Within." The reveal of Goliath's true identity comes with the revelation that an alternate Harry began the undoing of Earth's apocalyptic fate centuries into the future.

The shared alien appearance between Goliath and Harry is also revealed when Goliath's fossilized remains appear in season 2's art show. The character is indistinguishable from the scenes where Harry isn't presented as human due to the fact they are the same alien from different points in time. So, although Tudyk's official character count is 3, lurking in a dark corner of Resident Alien canon is Goliath also being played by the same actor.