My Little Pony/SpongeBob SquarePants

Version 1 (made by FlyingDuckManGenesis)

 * Rainbow Dash as Spongebob Squarepants (Random character choice XD)
 * Tank as Gary (Both have shells)
 * Pinkie Pie as Patrick (Both are Pink, start with the letter P, and both are random)
 * Rarity as Squidward (Both like clothing..?)
 * Twilight Sparkle as Mr.Krabs (She fits as a boss idk why :P)
 * Applejack as Sandy (Both have southern accents)
 * Big Mac as Larry (Both are red?)
 * Parasprites as the Jellyfishes (They both can fly)
 * Trixie as Plankton (Both are rivals with Mr Krabs and TS)
 * Flash Sentry as Mrs.Puff (Both are the love interest of Mr Krabs and TS)
 * Mr and Mrs Cake as Spongebob's Parents (..?)
 * Spitfire as Mermaidman (Both are idolized by RD and Spongebob)
 * Soarin as Barnicleboy (Both are idolized by RD and Spongebob)
 * Gilda as Bubble Bass (....)
 * Doctor Whooves as Jimmy (Don't know who Jimmy is)
 * Derpy Hooves as Tina (Who's Tina?)
 * Diamond Tiara as Pearl (Both are somehwat bratty?)
 * Silver Spoon as Karren (Random character choice XD)
 * Nightmare Moon as The Flying Dutchman (Both are...um..)
 * Princess Celestia as King Neptune (Both are royalty)
 * King Sombra as The Dirty Bubble (Random character choice XD)
 * Babs Seed as Bubble Buddy (Both start with "b")
 * Lyra Heartstrings as Fred (RCC XD)
 * Bob Bon as Tom (RCC XD)
 * Granny Smith as Spongebob's Grandma (They both are grandmas)
 * Sweetie Belle as Patchy (Both idolize RD and Spongebob)
 * Scootaloo as Potty (I dunno)
 * Discord as Man Ray (Both are evil)
 * Sunset Shimmer as Squilliam ( RCC XD)
 * Twilight's mom as Mr.Krabs' Mom (Both are their moms)
 * Lightning Dust as Flats (RCC XD)
 * Apple Family as The Plankton Family (RCC XD)

Version 2 (made by Skullzproductions)

 * Fluttershy as SpongeBob
 * Angel as Gary
 * Pinkie Pie as Patrick
 * Rarity as Squidward
 * Diamond Tiara as Mr.Krabs (Makes sense if you see The Krabby Kronicle & Ponyville Cofidential)
 * Applejack as Sandy
 * Big Mac as Larry
 * Parasprites as the Jellyfishes
 * Trixie as Plankton
 * Doctor Whooves as Jimmy
 * Derpy Hooves as Tina
 * Twilight Sparkle as Karen
 * King Sombra as The Flying Dutchman

Version 3 (made by BrittanCroftFan)

 * Snails as Spongebob Squarepants
 * Apple Bloom as Sandy Cheeks
 * Spike as Gary
 * Snips as Patrick Star
 * Shining Armor as Squidward Tentacles
 * Filthy Rich as Mr. Krabs
 * Big Mac as Larry
 * Parasprites as the Jellyfishes
 * Discord as Plankton
 * Cheerilee as Mrs. Puff (Both are Snails and Spongebobs teatchers)
 * Diamond Tiara as Pearl Krabs
 * Sunset Shimmer as K.A.R.E.N
 * Tirek (from G1) as The Flying Dutchman
 * Lord Solaris (from My Little Pony: Gender Swap) as King Neptune
 * Princess Celestia as Queen Amphitrite
 * Tony MC Brony (from Static Bunny) as Patchy the Pirate (Both are fans to MLP and Spongebob)
 * Dan (from Dan Vs.) as Potty the Parrot
 * Princess Cadance as Squilvia
 * Prince Blueblood as Squilliam Fancyson
 * Scorpan (from G1) as Lord Poltergeist
 * Silver Spoon as Judy
 * Background ponies as Backround fishes
 * Zacora as Madam Hagfish
 * Demon Snails as Ghost Spongebob
 * Demon Snips as Ghost Patrick
 * Mutants (from Spliced) as The Plankton Family

Version 4

 * Pinkie Pie as SpongeBob SquarePants (both are cheerful)
 * Gummy as Gary the Snail (pets to the cheerful character)
 * Derpy Hooves as Patrick Star
 * The Great & Powerful Trixie as Squidward Tentacles (both care about fame)
 * Discord as Mr. Krabs (Discord is reformed) (both were frozen/turned to stone at one point)
 * Applejack as Sandy Cheeks (both are Western)
 * King Sombra as Sheldon J. Plankton
 * Queen Chrysalis as K.A.R.E.N.
 * The Pony of Shadows as the Flying Dutchman
 * Rainbow Dash as Larry the Lobster (both are athletic)
 * Diamond Tiara as Pearl Krabs
 * Ms. Harshwhinny as Mrs. Puff
 * Gilda as Bubble Bass
 * Garble as Flatts
 * The Mysterious Mare-Do-Well as Mermaid Man
 * Daring Do as Barnacle Boy
 * The Mane-iac as Man Ray
 * Prince Blueblood as Squilliam Fancyson
 * Princess Celestia as King Neptune
 * Princess Luna as Triton
 * Princess Twilight Sparkle as Princess Mindy (both are young princesses)
 * The Diamond Dogs as Thugs of the Thug Tug
 * Ahuizotl as Dennis
 * Sunset Shimmer as the Cyclops
 * Flash Sentry as David Hasslehoff
 * Chancellor Puddinghead as SpongeBuck SquarePants