Agent Curtis

Agent Curtis first appears in the very first episode, "The Battle Begins"

Season One

 * "The Battle Begins" (first appearance)
 * "Expected"
 * "The Talented to Link"
 * "Kingdom Hearts"
 * "Tropic Thunder"
 * "Jackpot"
 * "Quest of the Luigi"
 * "Rayman on the Loose"
 * "Dillon Strikes"
 * "The Secrets of Skyloft"
 * "The Birth of the Victory"
 * "The Lost Chronicles"
 * "Super Smash Crisis"
 * "Fallen Hero"
 * "The Eye of Trip"
 * "Double Trouble Kings"
 * "Captain of the Guard"
 * "Invent Face-Off"
 * "Altitude Quickness"
 * "Shifting Burst"
 * "In the Name of the Hero-King"
 * "Dungeons & Dragons"
 * "Faster Than Time"
 * "The Last Forever"
 * "Burning Crusade"
 * "Cerberus"
 * "The Book of Spell"
 * "Strive for Peace"
 * "World of Warcraft"
 * "The Return of Wario-Man"
 * "Wrath of the Lich King"
 * "Marth's Revolution"
 * "Indigo League"
 * "Julie Take a Card"
 * "The Elf Princess and The Cute Penguin King"
 * "The Lightning Theif"
 * "Let's Make a Deal: Part 1"
 * "Let's Make a Deal: Part 2"
 * "Pair of Kings"
 * "The Mark of Athena"
 * "Hero of the Defenders"
 * "Bowser Jr. Returns"
 * "Clash of Clans"
 * "Eye of the Mercy"
 * "Level Up"

Season Two

 * "A Wizards of Place"
 * "Great Fox Defense"
 * "The Wedding"
 * "Application Beach"
 * "King of the Yoshis"
 * "Night Maid"
 * "When Penguin Smash"
 * "The Next Duel"
 * "Homecoming"
 * "Dual, Duel: Part 1"
 * "Dual, Duel: Part 2
 * "Players Bench"
 * "Below the Belt"
 * "Divide and Conquer"
 * "Enough with the Kidnapping"
 * "Jackpot Opportunity"
 * "New Challengers: Part 1"
 * "The Academy"
 * "Mirror Magic"
 * "The Lord of the Rings"
 * "Girls' Night Out"
 * "Duel Infinity: Part 1"
 * "Duel Infinity: Part 2"
 * "Shadow Mario Paint"
 * "Galaxia Darkness"
 * "The King Strikes Back"
 * "Tale of Two Marios"
 * "Legions of Falco"

Season Three

 * "A is for Arwing"
 * "C is for Coliseum"
 * "F is for Fighter"
 * "G is for Guardian"
 * "H is for Hunted"
 * "K is for Kingdom"
 * "L is for Legends"
 * "M is for Melee"
 * "N is for Norfair"
 * "Q is for Quest"
 * "T is for Titan"
 * "V is for Victory"
 * "W is for Warriors"
 * "Z is for Zero"

Season Four

 * "Bring it On"
 * "Worlds Apart"
 * "Back to the Future"
 * "All the News"
 * "Big Brother"
 * "Royal Pain"
 * "Getting Healthy"
 * "Bonding"
 * "Knowledge"
 * "Step by Step"
 * "Game On"
 * "Being Human"
 * "Simple"
 * "The Gauntlet"
 * "Keep 'Em off the Ship!"
 * "The Army of One"
 * "Black Out"
 * "Double Cross My Heart"
 * "On the Line"
 * "League of Legends"

Season Five

 * "The Battlefield Case"
 * "Furious Jealousy"
 * "The Lost Hero"
 * "The Ultimate Battle"
 * "Call of Duty"
 * "The Mindy Project"
 * "The Next Generation"
 * "And They Mario Will Be"
 * "The X-Factor"
 * "All That Glitters"
 * "Crush"
 * "Less Than Zero"
 * "Cool It"
 * "Exchange"
 * "My Girlfriend Katie and There's Gonna be Trouble"
 * "Eye of the Beholder"
 * "Shapeshifter"
 * "Game Over"

Season Six

 * "House of Dan"
 * "The Forces of Evil"
 * "Dan VS Felix"
 * "Student Zero"
 * "Parents' Night"
 * "The Prince of the Hyrule"
 * "Framed"
 * "Grande Size Me"
 * "Fight with a Disaster"
 * "Empire"
 * "A Piece of the Action"
 * "Mind Games"
 * "New Girl"
 * "Tick-Tick-Tick-Tick"
 * "Hyrule Castle or Bust"
 * "Number One"
 * "Double Trouble"
 * "Cold Case"
 * "Shadow Creatures"
 * "Eye for an Eye"
 * "The Ultimate Duel"

Season Seven

 * "Two Trouble Kings"
 * "Fastest, Shortest, Sudden Death"
 * "The Underwater Mines"
 * "Super Waterfall Climb"
 * "The Visitor to Flat Zone"
 * "The Yoshi Team of 50"
 * "Unwanted Suitors"
 * "Advent of the Evil King"
 * "Sonic and Mario"
 * "The Slow and Easy Life"
 * "Blades of the Quick and Mighty"
 * "The Hammer of the King"
 * "F.A.D.S."
 * "The Wolf Hunts the Fox"
 * "Face-Off"
 * "Landmaster Ignition"
 * "Super Bowser Bros."
 * "Shadow of Andross"

Season Eight

 * "Dungeons Card Battles"
 * "World Master"
 * "Family Ties"
 * "The Break of Day"
 * "Playing Tricks"
 * "Full Speed Ahead"
 * "An Offering of Coins"
 * "Scheming Sorcerer"
 * "Yellow Devils"
 * "The Destroyer Cometh"
 * "When Lightning Strikes"
 * "Robotic Rampage"
 * "Mechanical Menace"
 * "Solidarity"
 * "No Mere Sparring Match"
 * "Yesterday's Heroes"
 * "Identity Crisis"
 * "A Lurking Menace"
 * "Bird in Darkest Night"
 * "Wrecking Bros."

Season Nine

 * "Doorway to Battlefield"
 * "An Easy Win"
 * "The Mysteries of Zelda"
 * "Words of Truth"
 * "Two Powers Become One"
 * "Heart of Lies"
 * "Remote Control"
 * "Unlike Son"
 * "Past Perfect"
 * "Guilt for Free"
 * "No Girls Alone"
 * "Challenger of the Shadows: Part 1"
 * "Challenger of the Shadows: Part 2"
 * "Goddess of Light"
 * "The Future King"
 * "Champion of the Ring"
 * "Crossing Signals"
 * "The Swordsman"
 * "Behold of Destruction"

Season Ten

 * "I, Dan"
 * "Legendary Heroes"
 * "Supernatural Tuesday"
 * "Heroes VS Villains"
 * "Elementary"
 * "Breakout: Part 1"
 * "Breakout: Part 2"
 * "The Yoga of the Difinition"
 * "Oh No! Wario!"
 * "Walk This Way"
 * "Dream Warriors"
 * "Warriors of Hyrule"
 * "The Human Factor"
 * "Spells of Ashley"
 * "A New Hero Next Door"
 * "What Are Girl Made Of"
 * "The Legacy of Thor"
 * "Ill Suited"
 * "The Return of Meta Knight"
 * "Duel Hard"
 * "Son of the Battlefield"

Movies

 * "The Super Smash Bros. Movie"