Thaddeus

Secondary/cameo characters: Barnacle Boy • Billy • Dale • Dennis • Don • Evelyn • Flying Dutchman • Frank (Red Shirt Fish) • Fred • Harold • Realistic Fish Head • Larry the Lobster • Lifeguard • Mermaid Man • Patchy the Pirate • Potty the Parrot • Bikini Bottom Criminals

2-4 appearances: Rare/minor characters: Barbara • Billy • Billy Fishkins • Blue Fish • Bob • Bubble Bass • Bubble Buddy • Camera Man • Con Man • Construction Worker • Charlie • Elderly Snail • Frank (Store Owner) • Frank (Muscular Goldfish) • Frank (Prison Guard) • Grandma • Harold's Ex-Girlfriend • Harold Smith • Harold (To Love a Patty) • Harris • Hockey Players • Howard Blandy • Jack M. Crazyfish • Jim (Wrestler) • Joe • Judge Horace A. Whopper • Judy • Mable (Old Lady) • Mary • Mayor of Bikini Bottom • Mime •

One appearance:
Characters from old episodes: (seasons 1-5)
Administrator Flotsam • Betty • Big Johnny • Black Smith • Bruiser • Butler • Cave Fish • Clem • Criminal • Dave • Fortune Teller • Fran • Goofy Goober Waiter • Grubby Grouper • Help Wanted Lady • Hoopla Fish • Jeffrey Jellyfish • John • Judge StickleBack • Junior • King • Leech • Mary's Mother • Milo J. Finkerfish • Monster • Monty P. Moneybags
Characters from new episodes: (season 6 and newer) Abominable Snow Mollusk • Angry Jack • Bert • Bikini Bottom Bakery Cashier • Brain Gary • Brad • Bus Driver • Butler • Camp Counselor Kraus • Dance Judge • Endwight Keywad • Fancy McGee • Farfel Bainbridge • Fiasco • Flabby Patty Cook • Frederick T. Nitpick • Fuzzy Acorn • Glove World Owner • Gordon • Howard • Huford BargainBottom • Jack Kahuna Laguna • Jellion Clones • Jellion King • Jewel Triplets Gang • Karen 2.0 • Lion Fish • Little Girl • Little Kid • Ma Angler • Mable • Mailman • Madame Hag

Other characters: Miss Shell • Mr. Fitz • Mr. Normal • Mr. Ranger • Mr. What Zit Tooya • Mr. Whiskers • Music School Headmistress • Nancy • Nanny • Old Man Jenkins • Orville • Other Trenchbillies • Perch Perkins • Percha Perkins • Nat Peterson • Nat's Ex-Girlfriend • Not SpongeBob • Officer John • Officer Nancy • Pedro • Penny Pinchers • Percy Perch • Photographer • Producer • Quincy • Raarg • Realtor • Recreation Center Guard • Replacement Doctor • Richie Salmon • Sadie Rechid • Scooter • Shiny • Shubie • Singing Mermaids • Steve • Squilliam Fancyson • Squilvia • TattleTale Strangler • Thaddeus • The Appetizer • The Flying Dutchman's Date • The Olafs • Therapist • Timmy/Monroe • Tina • Tom • Tommy • Tyler • Toast-Fish • Tony Fast • Tony Fast Jr. • Trainer • Tourists • Vendor • Video Host • Wrestling Announcer
See Also: Villains • Bikini Bottom Criminals