The cardinal rule of every monster movie is that the monster can't look lame. That's why you hardly see the shark in Jaws, why Alien's Xenomorph sticks to the shadows and and why you seldom see Jason Voorhees without his hockey mask in the Friday The 13th franchise.

Typically, whenever Jason unmasks there is a discretionary shot blocking his true visage to make what you imagine under Jason's mask is significantly scarier than reality. While the vague, emotionless canvas of Jason Voorhees' hockey mask provides more abject terror than whatever monster mask was being worn underneath. However, the Friday The 13th franchise has given us a reasonable idea of what Jason has looked like underneath his hockey mask. Now, CBR is taking a look back at his increasingly less human appearance over the years.

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FRIDAY THE 13th (UNCUT)

Jason Voorhees from Friday The 13th (1980)

If you haven't seen 1980's Friday The 13th, you might not know that Jason isn't the original killer. Instead, it's his mom, Pamela Voorhees, who goes on a murderous rampage to avenge her son's death after Jason seemingly drowned in a nearby lake.

Jason (who was originally named Josh) appears during flashbacks and a dream sequence, where he's depicted as a bald child with facial deformities. However, it's worth noting that we never really get a close look at him in the original movie.

RELATED: Pamela Voorhees: The Dark Legacy of Friday the 13th's Original Killer

FRIDAY THE 13th: PART II

Jason Voorhees from Friday The 13th: Part 2

In 1981's Friday The 13th Part II, it's revealed that Jason never actually drowned. While Jason being alive makes no sense, it completely removes the impetus for Mrs. Voorhees' murder-spree,so the entire franchise hinges upon this plot hole.

For his villainous debut, Jason uses a sack with a hole in it as a mask. Under the sack-mask, Jason rocks a full head of Hagrid-esque hair and a bushy beard that covers much of his face. His over all appearance looks equally inspired by The Hills Have Eyes and Deliverance.

FRIDAY THE 13th PART III: 3D

Jason Unmasked Friday the 13th Part III

After his sack-mask drew comparisons to The Elephant Man, Jason got a modified Red Wings hockey mask for 1982's Friday The 13th Part III: 3D.

Jason's new mask reflected the emotionless force of nature that is Jason Voorhees. After ruthlessly pursuing all kinds of victims, Jason loses his mask, which reveals his a lopsided cranium and a grin full of nubby teeth. Gone is the force of nature; Jason is more of a monster than a human by this point, and he's just delighted to spread carnage.

FRIDAY THE 13TH PART IV: THE FINAL CHAPTER

Jason Voorhees from Friday The 13th: Part IV

In 1984's Friday The 13th Part IV: The Final Chapter, Jason Voorhees is supposedly unkillable by this point, he still dies since this movie is "the final chapter.:

During the final fight, Jason's mask is knocked off, which revealing an upgraded visage fairly similar to his previous incarnation. This time around, more emphasis is placed on Jason's now protruding right eye. Unfortunately, Jason's face still has a sort of rubbery, inauthentic feel to it.

FRIDAY THE 13TH PART V: A NEW BEGINNING

Roy impersonating Jason in Friday the 13th: Part V

A new Jason arises in 1985's Friday The 13th Part V: A New Beginning. By all counts, Tommy Jarvis, who was left traumatized and hallucinating after violently murdering Jason, seemed destined to pick up Jason's hockey mask in this sequel.

However, the faux Jason is actually Roy, the EMT whose mind was shattered upon seeing his son's corpse and constructs a hyper-realistic monster mask to replicate Jason's head. After killing another Jason, an insane Tommy puts on the mask, apparently moving the franchise in a bold new direction.

FRIDAY THE 13TH PART VI: JASON LIVES

Jason Voorhees unmasked from Friday The 13th Part VI: Jason Lives

For 1986's Friday The 13th Part VI: Jason Lives, Tommy exhumes Jason's body, just to ensure he's dead, as if the events of the last film never happened. During this, lightning strikes the metal pole in Jason's body and revives him.

Before Jason gets another mask, Tommy lights Jason on fire, giving us a long look at Jason's undead, maggot-filled face. Honestly, Jason looks like a melted Skeletor spray-painted black. Fortunately, this visage allows Jason's hockey mask to have two black pieces of fabric covering the eye-holes.

FRIDAY THE 13TH PART VII: THE NEW BLOOD

Jason Voorhees Unmasked from Friday The 13th Part VIII

For 1988's Friday The 13th Part VII: The New Blood Jason fights a psychokinetic teenager. This is the best designed Jason yet, as spending years at the bottom of Camp Crystal Lake has rotted away Jason's boiler suit and flesh, leaving bones peeking out throughout his tattered outfit.

During the final battle with the knock-off Carrie, Jason's mask splits, revealing a rotten face filled with disjointed, jagged teeth. There's also scars from all of the false deaths Jason has accumulated over the franchise: there's an exposed part of his skull with an empty eye socket that refelcts the machete gash that Jason had earned in Part II, a missing ear and an array of exposed molars from when he took a propeller to the face in Jason Lives and a jaundiced eye to contrast his rotten flesh.

FRIDAY THE 13TH PART VIII: JASON TAKES MANHATTAN

Jason Voorhees unmasked from Friday The 13th Part VIII: Jason Takes Manhattan

Jason is accidentally resurrected by a couple on a house boat anchored in Camp Crystal Lake. After killing them, he catches a ride with a teenager-filled cruise en route to Manhattan, where the last thirty minutes of 1989's Friday The 13th Part VIII: Jason Takes Manhattan take place.

In Times Square, Jason shows his face to a gang, in an effective gag that scares them away. By now, Jason's visage is a grey mess, melted by toxic sewage chemicals, sporting a viscous left eye and square teeth that makes it seem as if Jason has a Jack-O-Lantern face.

JASON GOES TO HELL: THE FINAL FRIDAY

Jason Goes To Hell Hell Baby

Jason returns once again in 1993's Jason Goes To Hell: The Final Friday. This second "final" film introduces some new rules about how Jason can be killed once and for all.

Jason's mask doesn't come off, since it has been permanently bonded to his flesh. Jason's bulbous head has grown around the straps of his mask, making his whole head look like a monster mask. At one point, Jason's host is decapitated, causing a demon tadpole-thing to climb out of his body in search of another host. Given the context, this is seemingly Jason's true form.

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JASON X

Jason X autopsy of Jason Voorhees (flipped image)

In 2001's Jason X, Jason goes to space after being cyrogenically frozen for centuries. We see what's under Jason's face when a scientist wearing lab-inappropriate clothes surgically removes the hockey mask to examine Jason's droopy eye in 2455 AD.

Since Jason X establishes that Jason has a healing factor, his face is more humanoid, featuring a nose and curly tufts of blonde hair, but missing lips and  with an eyelid over his protruding right eye.

FREDDY VS. JASON

Jason Voorhees from Freddy vs Jason (2003)

While fighting on the Dreamscape in 2003's Freddy vs. Jason, Freddy discovers that Jason has a repressed fear of water, stemming from his childhood drowning incident.

Anyway, Jason's face is only visible for a split second when the not-yet-murdered teenagers attempt to give Jason mouth-to-mouth resuscitation while he drowns within a dream. Jason now has a tuft of hair and blackened flesh, representing the dirt and/or hellfire that had been engulfing him since 1993.

FRIDAY THE 13TH (2009)

Jason Friday The 13th 2009

The 2009 reboot of Friday The 13th embraced the tropes established in its slasher roots, essentially retelling the first three films. The reboot changes things up however by making Jason's face legitimately horrifying.

During a quick glimpse through shadows, we see a hint of Jason's face: The flesh is raw and red, with a maw of gnawed teeth and a milky, droopy eye, topped off with wild locks of blonde hair.

No matter how scary he looks underneath the mask, Jason's face will always be, in many ways, the iconic hockey mask that he's worn for decades.