That which is the way the Kraang speak has become mutated by that which is known as the Internet into what is known as a meme.
The term "sadorable" has become extremely popular on Deviantart.
A certain preview for "Showdown" shows the Turtles and April having a little dance party. All three dances shown has become a bit memetic. So you know it shows Leo shuffling. Donnie and April, of all dances they could have done, doing the funky chicken. Then Raph's dance, which might be the most memetic of all.
"[Insert character name here] confirmed for season two!" To the point where fans will search for the most obscure characters possible to keep the joke going. It'll probably die down once season two actually comes along though.explanationThis originated from the writers announcing that Casey Jones would appear in season two before season one even aired.
Buzz buzz. explanationMichelangelo says this in the first episode of season two when dressed like a butterfly/moth.
The costumes the Turtles (and April) wore in the Halloween game featured on the Nick website. Especially Raph's fairy princess outfit.
Raphael: KING OF ALL PIGEONS!!!explanationIn "Follow The Leader", Raphael, using one pigeon, gets an entire flock of them to help assist in a stealth mission.
Raph (pretending to be Donnie): April's like an F5 key— She's so refreshing. Leo (pretending to be Mikey): OMG, you guys! Check out this giant gummy bear I found at the landfill! (Starts chewing at it wildly.)
Earlier in the same post is Mikey and Donnie acting out a mock fight between Leo and Raph respectively. The funny thing is it's pretty accurate to their relationship/arguments in other continuities.
Donnie (pretending to be Raph): You're always holding me back, Leo!! You don't understand me! Mikey, in reply to the above. (While pretending to be Leo): Uhhh, wait, Raph, I've stopped caring.
Earlier still.
Mikey (pretending to be Leo): I'm Leo. I enjoy fangirling and being serious.
"Don't Casetello me, bro!", "My Casetello vibes are tingling", and its variants to a lesser agree. explanation Casetello is the ship name for Casey/Donnie. Since both characters are memetic molesters these phrases are often used between fans to indicate that a second party is doing/acting/saying something creepy.
How did he build that? explanation First used in reference to Casey's seemingly endless ability to macguyver house hold objects into deadly weapons, and brought back to life when Raphael somehow managed to make duo flamethrowers with junk he found in the woods.
"Raphael is BEST Disney princess" explanation A combination of the above "Pigeon King" and Halloween costume memes
SAINW,nooooooooo!explanation The show has seemingly referenced the infamously sad/traumatizing 2003 serie episode "Same As It Never Was" several times. Fans have reacted appropriately.
Nightwatcher or Riot! explanation Raph's Nighwatcher persona that was introduced in the 2007 movie is notoriously popular within the fandom, and many fans wish to see this Raph become Nightwatcher.
Casey Jones: First psychotic human friend! explanation One of the many comments written on his concept art by the show runners.
PRAISE THE BEAN explanation Out of complete nowhere in November 2022, a screenshot of Leonardo, Donatello, and Raphael worshipping the bean-like wasp egg from "Parasitica" blew up on Twitter and became the center of its own religion. It was even popular enough to start trending on Twitter.
"Well, because I wanted us to fail. (Beat) OBVIOUSLY, I DIDN'T KNOW!"'' explanationDuring an attempt to destroy a Kraang device, Leo discovers it's protected by a force field and asks why Donnie didn't tell him, resulting in Donnie screaming this at him. The delivery of the line led to it taking off on TikTok as a reaction to questions with obvious answers.
When Raph is explaining his crush on Mona.
Mikey: "Wow, you really got a crush on that salamander hottie? She's, like, bigger, stronger, and probably a better fighter than you." Raph: "Exactly. What a woman." explanationThe interaction took off on TikTok as a way for users to show their attraction to physically strong female characters.
"Albert Einstein and Nikola Tesla." explanationThe opening music of the series is commonly used as a background theme song, along with a picture of Albert Einstein and Nikola Tesla put together, as a way to demonstrate people cheating physics with Loophole Abuse, or unconventional hacks for life.