S04E20: Were-Rats from Channel 6
After many failed attempts from his rodent subjects to find food, the Rat King learns of an abandoned canister of mutagen lost in the sewers and claims it for himself.
Previous Episode 
Season 1
Turtle Tracks
S1E1 / 14 Dec 1987
Enter: The Shredder
S1E2 / 15 Dec 1987
A Thing about Rats
S1E3 / 16 Dec 1987
Hot Rodding Teenagers from Dimension X
S1E4 / 17 Dec 1987
Shredder & Splintered
S1E5 / 18 Dec 1987
Season 2
Return of the Shredder
S2E1 / 01 Oct 1988
The Incredible Shrinking Turtles
S2E2 / 08 Oct 1988
It Came from Beneath the Sewers
S2E3 / 15 Oct 1988
The Mean Machines
S2E4 / 22 Oct 1988
Curse of the Evil Eye
S2E5 / 29 Oct 1988
The Case of the Killer Pizzas
S2E6 / 05 Nov 1988
Enter: The Fly
S2E7 / 12 Nov 1988
Invasion of the Punk Frogs
S2E8 / 19 Nov 1988
Splinter No More
S2E9 / 26 Nov 1988
New York's Shiniest
S2E10 / 03 Dec 1988
Teenagers from Dimension X
S2E11 / 10 Dec 1988
The Cat Woman of Channel Six
S2E12 / 17 Dec 1988
Return of the Technodrome
S2E13 / 24 Dec 1988
Season 3
Beneath these Streets
S3E1 / 25 Sep 1989
Turtles On Trial
S3E2 / 26 Sep 1989
Attack of the 50-Foot Irma
S3E3 / 27 Sep 1989
The Maltese Hamster
S3E4 / 28 Sep 1989
Sky Turtles
S3E5 / 29 Sep 1989
The Old Switcheroo
S3E6 / 02 Oct 1989
Burne's Blues
S3E7 / 03 Oct 1989
The Fifth Turtle
S3E8 / 04 Oct 1989
Enter: The Rat King
S3E9 / 05 Oct 1989
Turtles at the Earth's Core
S3E10 / 06 Oct 1989
April Fool
S3E11 / 09 Oct 1989
Attack of the Big MACC
S3E12 / 10 Oct 1989
The Ninja Sword of Nowhere
S3E13 / 11 Oct 1989
20.000 Leaks Under the City
S3E14 / 12 Oct 1989
Take Me to Your Leader
S3E15 / 13 Oct 1989
Four Musketurtles
S3E16 / 16 Oct 1989
Turtles, Turtles Everywhere
S3E17 / 17 Oct 1989
Cowabunga Shredhead
S3E18 / 18 Oct 1989
Invasion of the Turtle Snatchers
S3E19 / 19 Oct 1989
Camera Bugged
S3E20 / 20 Oct 1989
Green with Jealousy
S3E21 / 23 Oct 1989
Return of the Fly
S3E22 / 24 Oct 1989
Casey Jones: Outlaw Hero
S3E23 / 25 Oct 1989
Mutagen Monster
S3E24 / 26 Oct 1989
Corporate Raiders from Dimension X
S3E25 / 27 Oct 1989
Pizza by the Shred
S3E26 / 30 Oct 1989
Super Bebop & Mighty Rocksteady
S3E27 / 31 Oct 1989
Beware the Lotus
S3E28 / 01 Nov 1989
Blast from the Past
S3E29 / 02 Nov 1989
Leatherhead: Terror of the Swamp
S3E30 / 03 Nov 1989
Michaelangelo's Birthday
S3E31 / 06 Nov 1989
Usagi Yojimbo
S3E32 / 07 Nov 1989
Case of the Hot Kimono
S3E33 / 08 Nov 1989
Usagi Come Home
S3E34 / 09 Nov 1989
The Making of Metalhead
S3E35 / 10 Nov 1989
Leatherhead Meets the Rat King
S3E36 / 13 Nov 1989
The Turtle Terminator
S3E37 / 14 Nov 1989
The Great Boldini
S3E38 / 15 Nov 1989
The Missing Map
S3E39 / 16 Nov 1989
The Gang's All Here
S3E40 / 17 Nov 1989
The Grybyx
S3E41 / 20 Nov 1989
Mister Ogg Goes to Town
S3E42 / 21 Nov 1989
Shredderville
S3E43 / 22 Nov 1989
Bye Bye Fly
S3E44 / 23 Nov 1989
The Big Rip Off
S3E45 / 24 Nov 1989
The Big Break In
S3E46 / 27 Nov 1989
The Big Blow Out
S3E47 / 28 Nov 1989
Season 4
Plan Six From Outer Space
S4E1 / 10 Sep 1990
Turtles of the Jungle
S4E2 / 11 Sep 1990
Michaelangelo Toys Around
S4E3 / 12 Sep 1990
Peking Turtle
S4E4 / 13 Sep 1990
Shredder's Mom
S4E5 / 14 Sep 1990
Four Turtles and a Baby
S4E6 / 17 Sep 1990
Turtlemaniac
S4E7 / 18 Sep 1990
Rondo in New York
S4E8 / 19 Sep 1990
Planet of the Turtles
S4E9 / 20 Sep 1990
Name That Toon
S4E10 / 21 Sep 1990
Menace, Maestro Please
S4E11 / 28 Sep 1990
Superhero for a Day
S4E12 / 25 Sep 1990
Back to the Egg
S4E13 / 26 Sep 1990
Son of Return of the Fly II
S4E14 / 15 Sep 1990
Raphael Knocks 'em Dead
S4E15 / 15 Sep 1990
Bebop and Rocksteady Conquer the Universe
S4E16 / 22 Sep 1990
Raphael Meets His Match
S4E17 / 22 Sep 1990
Slash the Evil Turtle from Dimension X
S4E18 / 29 Sep 1990
Leonardo Lightens Up
S4E19 / 29 Sep 1990
Were-Rats from Channel 6
S4E20 / 13 Oct 1990
Funny, They Shrunk Michaelangelo
S4E21 / 13 Oct 1990
The Big Zipp Attack
S4E22 / 20 Oct 1990
Donatello Makes Time
S4E23 / 20 Oct 1990
Farewell, Lotus Blossum
S4E24 / 27 Oct 1990
Rebel Without a Fin
S4E25 / 27 Oct 1990
Rhino-Man
S4E26 / 03 Nov 1990
Michaelangelo Meets Bugman
S4E27 / 03 Nov 1990
Poor Little Rich Turtle
S4E28 / 10 Nov 1990
What's Michaelangelo Good For?
S4E29 / 10 Nov 1990
The Dimension X Story
S4E30 / 08 Sep 1990
Donatello's Degree
S4E31 / 08 Sep 1990
The Big Cufflink Caper
S4E32 / 14 Sep 1990
Leonardo VS Tempestra
S4E33 / 17 Nov 1990
Splinter Vanishes
S4E34 / 24 Nov 1990
Raphael Drives 'Em Wild
S4E35 / 24 Nov 1990
Beyond the Donatello Nebula
S4E36 / 01 Dec 1990
Big Bug Blunder
S4E37 / 01 Dec 1990
The Foot Soldiers Are Revolting
S4E38 / 08 Dec 1990
Unidentified Flying Leonardo
S4E39 / 08 Dec 1990
Season 5
The Turtles and the Hare
S5E1 / 23 Sep 1991
Once Upon a Time Machine
S5E2 / 24 Sep 1991
My Brother, the Bad Guy
S5E3 / 14 Sep 1991
Michaelangelo Meets Mondo Gecko
S5E4 / 14 Sep 1991
Enter: Mutagen Man
S5E5 / 21 Sep 1991
Donatello's Badd Time
S5E6 / 21 Sep 1991
Muckman Messes Up
S5E7 / 28 Sep 1991
Michaelangelo Meets Bugman Again
S5E8 / 28 Sep 1991
Napoleon Bonafrog: Colossus of the Swamps
S5E9 / 05 Oct 1991
Raphael VS The Volcano
S5E10 / 05 Oct 1991
Landlord of the Flies
S5E11 / 19 Oct 1991
Donatello's Duplicate
S5E12 / 19 Oct 1991
The Ice Creature Cometh
S5E13 / 26 Oct 1991
Leonardo Cuts Loose
S5E14 / 26 Oct 1991
Pirate Radio
S5E15 / 02 Nov 1991
Raphael, Turtle of a Thousand Faces
S5E16 / 02 Nov 1991
Zach and the Alien Invaders
S5E17 / 09 Nov 1991
Leonardo, the Renaissance Turtle
S5E18 / 09 Nov 1991
Welcome Back, Polarisoids
S5E19 / 16 Nov 1991
Michaelangelo, the Sacred Turtle
S5E20 / 16 Nov 1991
Planet of the Turtleloids, Part 1
S5E21 / 31 Aug 1990
Planet of the Turtleloids, Part 2
S5E22 / 31 Aug 1990
Season 6
Rock Around the Block
S6E1 / 14 Sep 1992
Krangenstein Lives!
S6E2 / 21 Sep 1992
Super Irma
S6E3 / 03 Oct 1992
Adventures in Turtle-Sitting
S6E4 / 10 Oct 1992
Sword of Yurikawa
S6E5 / 16 Oct 1992
Return of the Turtleoids
S6E6 / 23 Oct 1992
Shreeka's Revenge
S6E7 / 30 Oct 1992
Too Hot to Handle
S6E8 / 05 Nov 1992
Nightmare in the Lair
S6E9 / 12 Nov 1992
Phantom of the Sewers
S6E10 / 19 Nov 1992
Donatello Trashes Slash
S6E11 / 25 Nov 1992
Leonardo Is Missing
S6E12 / 02 Dec 1992
Snakes Alive!
S6E13 / 09 Dec 1992
Polly Wanna Pizza
S6E14 / 15 Dec 1992
Mr. Nice Guy
S6E15 / 22 Dec 1992
Sleuth on the Loose
S6E16 / 29 Dec 1992
Season 7
Tower of Power
S7E1 / 18 Sep 1993
Rust Never Sleeps
S7E2 / 18 Sep 1993
A Real Snow Job
S7E3 / 25 Sep 1993
Venice on a Half Shell
S7E4 / 25 Sep 1993
Artless
S7E5 / 02 Oct 1993
Ring of Fire
S7E6 / 02 Oct 1993
The Irish Jig Is Up
S7E7 / 09 Oct 1993
Shredder's New Sword
S7E8 / 09 Oct 1993
The Lost Queen of Atlantis
S7E9 / 16 Oct 1993
Turtles on the Orient Express
S7E10 / 16 Oct 1993
April Gets in Dutch
S7E11 / 23 Oct 1993
Northern Lights Out
S7E12 / 23 Oct 1993
Elementary, My Dear Turtle
S7E13 / 30 Oct 1993
Night of the Dark Turtle
S7E14 / 30 Oct 1993
The Starchild
S7E15 / 06 Nov 1993
The Legend of Koji
S7E16 / 06 Nov 1993
Convicts from Dimension X
S7E17 / 13 Nov 1993
White Belt, Black Heart
S7E18 / 13 Nov 1993
Night of the Rogues
S7E19 / 20 Nov 1993
Attack of the Neutrinos
S7E20 / 20 Nov 1993
Escape from the Planet of the Turtleloids
S7E21 / 27 Nov 1993
Revenge of the Fly
S7E22 / 27 Nov 1993
Atlantis Awakes
S7E23 / 04 Dec 1993
Dirk Savage: Mutant Hunter
S7E24 / 04 Dec 1993
Invasion of the Krangezoids
S7E25 / 11 Dec 1993
Combat Land
S7E26 / 11 Dec 1993
Shredder Triumphant
S7E27 / 18 Dec 1993
Season 8
Get Shredder!
S8E1 / 17 Sep 1994
Wrath of the Rat King
S8E2 / 24 Sep 1994
State of Shock
S8E3 / 01 Oct 1994
Cry H.A.V.O.C.!
S8E4 / 08 Oct 1994
H.A.V.O.C. in the Streets
S8E5 / 15 Oct 1994
Enter: Krakus
S8E6 / 22 Oct 1994
Cyber-Turtles
S8E7 / 29 Oct 1994
Turtle Trek
S8E8 / 05 Nov 1994
Season 9
The Unknown Ninja
S9E1 / 16 Sep 1995
Dregg of the Earth
S9E2 / 23 Sep 1995
The Wrath of Medusa
S9E3 / 30 Sep 1995
The New Mutation
S9E4 / 07 Oct 1995
The Showdown
S9E5 / 14 Oct 1995
Split-Second
S9E6 / 21 Oct 1995
Carter the Enforcer
S9E7 / 28 Oct 1995
Doomquest
S9E8 / 04 Nov 1995
Season 10
The Return of Dregg
S10E1 / 14 Sep 1996
The Beginning of the End
S10E2 / 21 Sep 1996
The Power of Three
S10E3 / 28 Sep 1996
A Turtle in Time
S10E4 / 05 Oct 1996
Turtles to the Second Power
S10E5 / 12 Oct 1996Mobster from Dimension X
S10E6 / 19 Oct 1996
The Day the Earth Disappeared
S10E7 / 26 Oct 1996
Divide and Conquer
S10E8 / 02 Nov 1996
Cam Clarke
Leonardo (voice)
Barry Gordon
Donatello (voice)
Townsend Coleman
Michaelangelo (voice)
Michael Gough
Raphael (voice)
Peter Renaday
Splinter (voice)
Renae Jacobs
April O'Neil (voice)
Tony Jay
Dregg (voice)
