Charlie McFadden is known in Grover's Bend as the town drunk, who believes in extraterrestrials and frequently claims to be in contact with them via his teeth or headaches. Charlie works with Jay Brown on his vehicles at the Brown farm, where he talks with his one and only friend, Bradley Brown. He accidentally shoots April Brown with Brad's slingshot, but Brad gets punished for it. On the way home that night, Charlie witnesses a spaceship in the sky. He cycles back to town in a panic, pleading with Sal to call the army; although his ramblings are dismissed as being drunk.
Charlie goes to the town's bowling alley for a drink, but his suspicions are confirmed when the Bounty Hunters appear and mimic Charlie's appearance, freaking him out. He then follows them back to the Brown farm, where the Crites are just getting ready to leave. He helps Brad get April out of the ship, and lights his bottle of whiskey as a molotov cocktail and throws it through the ship's door, igniting Brad's firecracker and destroying the ship.
As the Bounty Hunters leave, Charlie is seen following them, asking for a Communicator like the one they gave to Brad.
- Main: Space Charlie
Over two years after the events of the first film, Brad Brown (Scott Grimes) is now 15, and returns to Grovers Bend to spend Easter Weekend with his Grandma. Leftover Crite eggs that were in Brad's old farm are taken and mistaken for Easter eggs, unleashing the Crites onto the entire town. Ug, Zanti and the former drunk Charlie (Don Keith Opper), return from space to help Grover's Bend.
- Main: Critter Hunter Charlie
Sometime after the events in Critters 2, Charlie MacFadden is tracking down the last of the Critters. A family of three – Annie (the main protagonist), Johnny (her little brother) and Clifford (the father) – stops at a rest stop when their car's tire pops. At the rest stop, Critter Hunter Charlie warns them and Josh, stepson of a corrupt landlord, about the Critters. As this happens, a Critter lays eggs under the family's car and the family leaves, unknowingly taking the eggs with them. Soon after they arrive at their tenement, the Critters hatch and attack the sleazy maintenance man, Frank. When the landlord arrives, he too is eaten by the Critters after Josh locks him in Clifford's room, unknowingly trapping his stepfather with the creatures. Next, one of the residents is attacked and wounded. Annie, her family and five others (including Josh) try to get to safety in one piece by getting to the roof of the building. Charlie arrives and destroys the remaining Critters, saving the remaining tenants. The film ends in a cliffhanger as Charlie is about to destroy two Critter eggs, but is ordered not to and a containment pod sent from the Intergalactic Council crashes into the basement.
- Main: Future Charlie
Picking up exactly where Critters 3 left off, Critter Hunter Charlie, is about to fire his gun on the last two Critter-eggs when he gets a message that it would be illegal to extinguish the race from the galaxy. A transporter is sent to him, where he puts the eggs in. However, the transporter also takes him with it where he then gets lost in space. After 53 deep-frozen years, he's found by a private wreckage collector team, captained by the unscrupulous Rick. On behalf of the mighty company Terracor they bring him to an empty space station - but Rick is curious and opens Pandora's box... now Future Charlie has work again, to keep the Critters from eating everybody.