Level Modulation
Originally appearing in a manga, this fairy has been an important part of the meta since its release in Lightning Overdrive.
Diviner of the Heralds
If the battle position of this card is changed: You can Special Summon 1 Insect monster from your hand or GY in Defense Position.
Number 3: Cicada King
In this Adult swim comedy show, this pendulum monster and her grandson are all about that that McDonalds Szechuan Sauce.
Archfiend Eccentrick and Morty
This was the 7th samurai of the original six.
Floowandereeze
Floowandereeze and the Scary Sea
This synchro monster is better known from Swordsoul for its ability to negate backrow
Adamancipator Risen - Dragite
This beast-warrior was known in old formats for making Constellar Pleiades
Constellar Kaus
Once per turn: You can discard 1 Spell; the monster Special Summoned by this card's effect gains ATK/DEF equal to its original ATK/DEF, until the end of your opponent's turn.
Brilliant Fusion
Kaiba tales. Kaiba tales. It's almost time for Kaiba tales. Come along and take my ha.d Let's all go to Kaiba Land.
Blue-Eyes White Dragon Tales
Herald of Orange Light
Flamvell
Flamvell Counter
When Grinder Golem was legal, this secret rare from Circuit Break let you put it back in your hand to loop again.
Akashic Magician
Level modulation is something this spell can do, though it's better known for its searching and Magical Meltdown-like protection effect
Drytron Fafnir
If this face-up card is destroyed by battle, or leaves the field because of an opponent's card effect while its owner controls it: You can target 1 card in your GY; add it to your hand.
Curious, the Lightsworn Dominion
Blossom, Bubbles, and Buttercup make onomatopoeia and rank 4s in this classic Cartoon Network show.
The Powerpuff Gagaga Girls
With the right setup, you can use this card's effect to search infinitely
Gateway of the Six
Earthbound Immortal
Earthbound Wave
This level 7 saw play in Blue-Eyes as a monster to summon off Blue-Eyes Spirit Dragon
Black Rose Moonlight Dragon
First appearing as a TCG exclusive, this card was integral to the original Wind-up hand loop, as it easily let you trigger multiple Wind-up Magicians
Wind-up Shark
Target 1 "Shaddoll" monster in your GY; Special Summon it in face-up or face-down Defense Position.
Resh Shaddoll Incarnation
Stupid continuous spell! You make me look bad
This card was used to artificially extend the effect of a single Chicken Game
Pseudo Space
Assault Mode
Assault Counter
Scrap Twin Dragon
Star Changer
Once per turn (Quick Effect): You can remove 3 Kaiju Counters from anywhere on the field; the ATK/DEF of all other monsters on the field become halved.
Gadarla, the Mystery Dust Kaiju
This Cartoon Network classic tells the story of a furry mercenary who tries to get women to date him.
Johnny Bravo, Fighter Fur Hire
One of the most powerful cards of the modern age, this tcg exclusive didn't see play upon its initial release, despite being part of a format perfectly suited for it.
Maxx "c"
Koa'ki Meiru (2 answers accepted)
Iron Core Luster/Nega-Ton Corepanel
In the anime, this card was so formidable it caused Avian and Sparkman to form a guy-pact.
Burst Return