This is how Thunderblast meets the Mutant Pumpkins goes in Thomas' Monsterific Halloween.
[One night an unidentified flying object (UFO) appears on Earth and drops a strange green goo into a large pumpkin field. After it jets back into space, the Decepticon Thunderblast comes to investigate]
Thunderblast: My, my, my. Who would leave all this goo here?
[Pumpkins all around sprout arms, legs, eyes and mouths]
Thunderblast: My own army of mutant Pumpkins!
[A farmer, Farmer Jeb, comes out to investigate]
Thunderblast: Uh-oh! Quick, my pumpkin army. Resume being normal and lifeless till I give you the signal.
[The pumpkins go back to normal and Farmer Jeb walks towards Thunderblast]
Thunderblast: Don't mind me. I'm just an Autobot.
Farmer Jeb: But why do you have a Decepticon logo?
Thunderblast: I'm just getting ready for Halloween. Yeah. That's it.
[But she signals the pumpkins and they resprout arms, legs, eyes and mouths]
Farmer Jeb: What the?
Thunderblast: [sinister chuckle] Pumpkins, tie him up.
[The Mutant Pumpkins sprout back to life and do so]
Ryvine Sparkle: Nice one, Thunderblast.
Ryvine Sparkle: I haven't say my name. I'm Ryvine Sparkle.
Thunderblast: Nice to meet you.
Ryvine Sparkle: Why are the pumpkins alive? I can command the Plunder Vines like my sister does.
Thunderblast: I saw something drop goo on them.
Ryvine Sparkle: Me too. You ever heard of Princess Twivine Sparkle?
[Thunderblast shakes her head for "No"]
Ryvine Sparkle: Well, she's my sister. She has the power to control Plunder Vines.
[Twivine comes over]
Ryvine Sparkle: Speak of the Dalek. Here she is.
Twivine Sparkle: Nice to meet you.
Ryvine Sparkle: Hi, sis. This is Thunderblast. Thunderblast, Twivine. I'll do some testing of my plundervines.
[Ryvine does as the two females converse]
Ryvine Sparkle: Yeah. I can use them to drain magic.
[Ryvine commands the plunder vines to drain the magic from a pumpkin]
Ryvine Sparkle: What do you think? Pretty cool.
Ryvine Sparkle: Yeah. You pumpkins wait until Nightmare Night.
[One of the pumpkins plants a sign that says "Thomas' Monsterific Halloween"]
Twivine Sparkle: Wow! That's a title?
Thunderblast: Well. I'll have you two helping me.
[They begin scheming as the screen fades to black. The song "This is Nightmare Night" starts playing]
Twilight Sparkle: Fillies and colts of every age~
Bob Cooper: Would you like to see something strange?~
Bumblebee: Come with us and you will see~
Bentley: This is one frightful Nightmare Night~
Matau T. Monkey: This is Nightmare Night~
Pinkie Pie: This is Nightmare Night~
Evil Ryan: Pumpkins scream in the dead of night~
Thomas: This is Nightmare Night~
Murray: Everypony make a scene~
Applejack: Trick or treat~
Bertram T. Monkey: Till the neighbors gonna die of fright~
Evil Anna: It's our town, everybody scream~
Jessica Fairbrother: Nightmare Night is on the scene~
Spike: You may find something hiding under you bed~
Scootaloo: Teeth ground sharp and eyes glowing red~
Brian the Crocodile: There may be something under your stairs~
Fingers like snakes and spiders in it's hair~
Sweetie Belle: This is Nightmare Night~
Salim al-Kupar: This Nightmare Night~
Garfield: Nightmare Night~
Discord: Nightmare Night~
12th Doctor: Nightmare Night~
Sly Cooper: Nightmare Night~
Rioichi Cooper: In this town, we call home~
Everyone hail to the Nightmare song~
Tennessee Kid Cooper: In this town, don't we love it now~
Sci-Ryan and Tennessee Kid Cooper: Everypony's waiting for the next surprise~
Applebloom: Round that corner, colts hiding in the trash can~
Batman (The LEGO Movie): Something's waiting now to pounce and how you'll~
Sunset Shimmer: Scream!~
Sunshine (Salty's Lighthouse Version): This is Nightmare Night~
Oswald the Lucky Rabbit: Creepy slime~
Cody Fairbrother: Black and white~
Pinkie Pie: AREN'T YOU SCARED?!~
Buck the Wiesel and Buck the Wiesel (EG): Well that's just fine~
Trixie: Say it once~
Garfield: Say it twice~
Twilight Sparkle: Take the chance~
Darksteel: And roll the dice~
Skylynx: Ride with the moon in the dead of night~
Rarity: Everypony scream, everypony scream~
Timothy (Non-ghost engine version): Nightmare Night is on the scene~
Crash Bandicoot: Here is the clown with the tear-away face~
Thomas: Here in a flash and gone without a trace~
Ten Cents: A ghost is the "who" when you call "Who's there?"~
He is the wind blowing through your hair~
Rainbow Dash: Oogie Boogie is the shadow on the moon at night~
Airachnid (under the Cyberlings' spell): Filling your dreams to the brim with fright~
Sour Sweet: This is Nightmare Night~
Indigo Zap: This is Nightmare Night~
Emmet: Nightmare Night~
Wyldstyle: Nightmare Night~
Lemon Zest: Nightmare Night~
Sally Contralto: Nightmare Night~
The Cyberlings: Spooky creatures everywhere~
Sir Daniel Fortesque: Everyone's out to scream and scare~
Diesel 10: That's our job~
King Sombra: You got that right~
Dr. Robotnik: In this town on Nightmare Night~
Penelope (Sly Cooper): In this town, don't we love it now?~
Bentley and Penelope (Sly Cooper): Everypony's waiting for the next surprise~
Prince Can: Nightmare Moon might catch you in your room and..~
Princess Graciella: Scream like a banshee and make you jump~
The Dazzlings: Out of your skin~
Optimus Prime: This is Nightmare Night~
Ryan and the Rainbooms: Won't you please make way for royalty?~
Sci-Ryan, Ryan and the Dazzlings: Nightmare Moon is queen of the nightmares now~
Everypony hail to the nightmare queen now~
Smokescreen: This is Nightmare Night~
Matau and the Skylanders: This is Nightmare Night~
Fluttershy: Nightmare Night~
Sideswipe: Nightmare Night~
Murray: Nightmare Night~
Thomas: Nightmare Night~
The CMC: In this town, we call home~
Scorpan: Everypony hail to the Nightmare song~
Everyone: La la-la la, Nightmare Night! Nightmare Night! [Repeat]
Sci-Ryan and Odette: WEE!!!
Rainbow Dash: Awesome!
Sci-Ryan: That's a cool song.
Matau T. Monkey: I hope we can do the Friendship Games.
Ryan F-Freeman: Or might I suggest: Crash, Thomas, Ryan and the Swan Princess Christmas?
[Matau nods and hugs Ryan and Odette]