Sheldon J. Plankton/appearances

Character

Gallery

Appearances

Plankton was first created by Stephen Hillenburg as a potential villain for the show. However, he later feared that Plankton's stories would get repetitive and predictable. During the production of season one, Hillenburg demoted Plankton from a main character to a minor one; he insisted that Plankton would work better as a one-time guest star.

However, Doug Lawrence loved the character. He summarized Plankton's origins in 2015, saying that he "was only supposed to be in one or two episodes, but I was a writer on the show and I really liked this character." Lawrence wrote episode ideas for Plankton and passed them to Hillenburg. From then on, Plankton began to appear more often. Lawrence's most notable contribution was giving a personality to Plankton's "waterproof computer," named Karen after Stephen Hillenburg's wife. He decided that Plankton and Karen should be an inseparable duo, with Karen as the brains of the operation, always supplying Plankton with evil plans.

Since Plankton's "reinvention" by Lawrence, he and Karen have appeared in many episodes. They were both officially promoted to main characters in the credits of the 2004 film and have been part of the main cast ever since. Plankton has also appeared in various video games.

Episodes

Image	#	Episode	Role in episode
Season 1
	3b	"Plankton!" (tr • ga)	Major
	10a	"Culture Shock" (tr • ga)	Minor
	10b	"F.U.N." (tr • ga)	Major
	15a	"Sleepy Time" (tr • ga)	Supporting
	16a	"Valentine's Day" (tr • ga)	Non-speaking cameo
	18b	"Walking Small" (tr • ga)	Major
Season 2
	24b	"Imitation Krabs" (tr • ga)	Major
N/A	27b	"Life of Crime" (tr • ga)	Mentioned
	28	"Christmas Who?" (tr • ga)	Cameo
	34a	"Welcome to the Chum Bucket" (tr • ga)	Major
	35b	"Band Geeks" (tr • ga)	Supporting
	39b	"The Fry Cook Games" (tr • ga)	Major
Season 3
	41a	"The Algae's Always Greener" (tr • ga)	Major
	45a	"Mermaid Man and Barnacle Boy IV" (tr • ga)	Cameo
	46a	"Snowball Effect" (tr • ga)	Cameo
	50b	"Krusty Krab Training Video" (tr • ga)	Supporting
	51	"Party Pooper Pants" (tr • ga)	Supporting
	58b	"Plankton's Army" (tr • ga)	Major
	59	"The Sponge Who Could Fly" (tr • ga)	Minor
	60a	"SpongeBob Meets the Strangler" (tr • ga)	Cameo
Season 4
	61a	"Fear of a Krabby Patty" (tr • ga)	Major
	62b	"Krabs vs. Plankton" (tr • ga)	Major
	66	"Dunces and Dragons" (tr • ga)	Major, medieval ancestor appears instead
	67a	"Enemy In-Law" (tr • ga)	Major
	67b	"Mermaid Man & Barnacle Boy VI: The Motion Picture" (tr • ga)	Minor
	68a	"Patrick SmartPants" (tr • ga)	Cameo
	72b	"Wishing You Well" (tr • ga)	Supporting
	73a	"New Leaf" (tr • ga)	Major
	78b	"Best Frenemies" (tr • ga)	Major
Season 5
	81	"Friend or Foe" (tr • ga)	Major
	84a	"Spy Buddies" (tr • ga)	Major
	85b	"Krabs à la Mode" (tr • ga)	Major
	86b	"Bucket Sweet Bucket" (tr • ga)	Major
	91a	"Goo Goo Gas" (tr • ga)	Major
	92	"Atlantis SquarePantis" (tr • ga)	Major
	94b	"Mermaid Man vs. SpongeBob" (tr • ga)	Major
	97a	"20,000 Patties Under the Sea" (tr • ga)	Major
	100a	"Banned in Bikini Bottom" (tr • ga)	Major
	100b	"Stanley S. SquarePants" (tr • ga)	Cameo
Season 6
	101b	"Krabby Road" (tr • ga)	Major
	103a	"Spongicus" (tr • ga)	Major
	108a	"Patty Caper" (tr • ga)	Minor
	108b	"Plankton's Regular" (tr • ga)	Major
	109b	"The Krabby Kronicle" (tr • ga)	Minor
	118b	"Komputer Overload" (tr • ga)	Major
	122a	"Chum Bucket Supreme" (tr • ga)	Major
	122b	"Single Cell Anniversary" (tr • ga)	Major
	123-124	"Truth or Square" (tr • ga)	Major
	125b	"Chum Caverns" (tr • ga)	Major
Season 7
	127a	"Tentacle-Vision" (tr • ga)	Minor
	129a	"Someone's in the Kitchen with Sandy" (tr • ga)	Major
	129b	"The Inside Job" (tr • ga)	Major
	130a	"Greasy Buffoons" (tr • ga)	Major
	134	"SpongeBob's Last Stand" (tr • ga)	Major
	137a	"One Coarse Meal" (tr • ga)	Major
	138a	"The Play's the Thing" (tr • ga)	Non-speaking cameo
	138b	"Rodeo Daze" (tr • ga)	Supporting
	139a	"Gramma's Secret Recipe" (tr • ga)	Major
	140b	"Welcome to the Bikini Bottom Triangle" (tr • ga)	Minor
	141b	"The Main Drain" (tr • ga)	Supporting
	143	"The Great Patty Caper" (tr • ga)	Major
	144a	"That Sinking Feeling" (tr • ga)	Cameo
	145a	"Buried in Time" (tr • ga)	Supporting
	147b	"Shellback Shenanigans" (tr • ga)	Major
	152b	"Perfect Chemistry" (tr • ga)	Major
Season 8
	153b	"The Other Patty" (tr • ga)	Major
	154a	"Drive Thru" (tr • ga)	Minor
	156	"Frozen Face-Off" (tr • ga)	Major
	157a	"Squidward's School for Grown-Ups" (tr • ga)	Cameo
	158a	"Sweet and Sour Squid" (tr • ga)	Major
	159	"A SquarePants Family Vacation" (tr • ga)	Cameo
	160b	"Walking the Plankton" (tr • ga)	Major
	163b	"Plankton's Good Eye" (tr • ga)	Major
	167a	"The Krabby Patty That Ate Bikini Bottom" (tr • ga)	Minor
	168b	"Fiasco!" (tr • ga)	Major
	170a	"Free Samples" (tr • ga)	Major
	171a	"Karen 2.0" (tr • ga)	Major
	174b	"For Here or to Go" (tr • ga)	Major
	175	"It's a SpongeBob Christmas!" (tr • ga)	Major
	176a	"Super Evil Aquatic Villain Team Up is Go!" (tr • ga)	Major
	176b	"Chum Fricassee" (tr • ga)	Major
	177a	"The Good Krabby Name" (tr • ga)	Cameo
	177b	"Move It or Lose It" (tr • ga)	Major
	178	"Hello Bikini Bottom!" (tr • ga)	Cameo
Season 9
	179b	"Squirrel Record" (tr • ga)	Minor
	183a	"Eek, an Urchin!" (tr • ga)	Major
	184a	"Jailbreak!" (tr • ga)	Major
	184b	"Evil Spatula" (tr • ga)	Major
	185	"It Came from Goo Lagoon" (tr • ga)	Major
	186b	"Plankton's Pet" (tr • ga)	Major
	192a	"Company Picnic" (tr • ga)	Major
	196b	"Married to Money" (tr • ga)	Major
	198b	"CopyBob DittoPants" (tr • ga)	Major
	199b	"Lame and Fortune" (tr • ga)	Major
	200	"Goodbye, Krabby Patty?" (tr • ga)	Minor
	203a	"Pineapple Invasion" (tr • ga)	Major
	203b	"Salsa Imbecilicus" (tr • ga)	Major
	204a	"Mutiny on the Krusty" (tr • ga)	Non-speaking cameo
Season 10
	207a	"Mimic Madness" (tr • ga)	Supporting
	207b	"House Worming" (tr • ga)	Minor
	209b	"Plankton Gets the Boot" (tr • ga)	Major
	210b	"Burst Your Bubble" (tr • ga)	Supporting
	211a	"Plankton Retires" (tr • ga)	Major
	212a	"The Incredible Shrinking Sponge" (tr • ga)	Minor
N/A	215a	"Feral Friends" (tr • ga)	Deleted scene
Season 11
	217a	"Spot Returns" (tr • ga)	Major
	218a	"Spin the Bottle" (tr • ga)	Major
	220	"The Legend of Boo-Kini Bottom" (tr • ga)	Supporting
	221a	"No Pictures Please" (tr • ga)	Supporting
	222a	"Krabby Patty Creature Feature" (tr • ga)	Supporting
	222b	"Teacher's Pests" (tr • ga)	Major
N/A	228a	"Fun-Sized Friends" (tr • ga)	Mentioned
	228b	"Grandmum's the Word" (tr • ga)	Major
	230b	"Bottle Burglars" (tr • ga)	Major
	232b	"Shopping List" (tr • ga)	Major
	234a	"Patnocchio" (tr • ga)	Major
	235a	"Plankton Paranoia" (tr • ga)	Major
	236a	"Call the Cops" (tr • ga)	Major
	236b	"Surf N' Turf" (tr • ga)	Minor
	238a	"Appointment TV" (tr • ga)	Supporting
	238b	"Karen's Virus" (tr • ga)	Major
	239a	"The Grill is Gone" (tr • ga)	Minor
	240b	"Girls' Night Out" (tr • ga)	Supporting
Season 12
	242b	"Gary & Spot" (tr • ga)	Minor
	244a	"The Krusty Slammer" (tr • ga)	Major
	245b	"King Plankton" (tr • ga)	Major
	246a	"Plankton's Old Chum" (tr • ga)	Major
	248a	"The Krusty Bucket" (tr • ga)	Major
	249a	"Sandy's Nutty Nieces" (tr • ga)	Likeness only
	250b	"Karen's Baby" (tr • ga)	Major
	251b	"Senior Discount" (tr • ga)	Minor
	254-255	"SpongeBob's Big Birthday Blowout" (tr • ga)	Supporting
	257a	"Handemonium" (tr • ga)	Major
	259a	"The Ghost of Plankton" (tr • ga)	Major
	259b	"My Two Krabses" (tr • ga)	Minor
	261b	"Hiccup Plague" (tr • ga)	Minor
	262b	"The Hankering" (tr • ga)	Supporting
	263a	"Who R Zoo?" (tr • ga)	Minor
	263b	"Kwarantined Krab" (tr • ga)	Minor
	264a	"Plankton's Intern" (tr • ga)	Major
	267b	"Dream Hoppers" (tr • ga)	Cameo in Mr. Krabs' dream (non-speaking)
Season 13
	268a	"A Place for Pets" (tr • ga)	Minor
	268b	"Lockdown for Love" (tr • ga)	Major

Shorts

Image	#	Episode	Role in episode
		"Plankton's Holiday Hits" (tr • ga)	Major
		"Can't Swim" (tr • ga)	Supporting
		"Remodeling" (tr • ga)	Supporting
		"Loop dee Loop" (tr • ga)	Minor
		"Plankton Pays" (tr • ga)	Major
		"SpongeBob's Legendary Dance Party" (tr • ga)	Minor
		"Plankton's Color Nullifier" (tr • ga)	Major

Movies

Image	#	Episode	Role in episode
	F1	"The SpongeBob SquarePants Movie" (tr • ga)	Major
	F2	"The SpongeBob Movie: Sponge Out of Water" (tr • ga)	Major
	F3	"The SpongeBob Movie: Sponge on the Run" (tr • ga)	Major

Miscellaneous

• SpongeBob SquarePants 4-D: Ride
• SpongeBob SquarePants 4-D: The Great Jelly Rescue!