Youngblood is portrayed as a child ghost who likes to dress-up. He has an assistant, a skeleton-like shapeshifter who takes the form of animals who go along with these characters, like when Youngblood was a pirate, his shapeshifter was a parrot, then later a horse when Youngblood was a cowboy.
Youngblood makes his first appearance in "Pirate Radio", where he and his crew steal various technological gear (the Fenton's Ghost Shield Generator and treadmills) to create a ghost shield around his pirate ship while using the treadmills for adults to use to power his ship, entranced and lured by his partner in crime, Ember McLain. However, Danny and a host of other kids his age work together to eventually end Youngblood's scheme, trapping him inside his own pirate ship with his parrot and crew via the ghost shield and having it sent to the bottom of the ocean.
Youngblood and his parrot, now shapeshifted into a horse, escape in "The Fenton Menace" where he is now dressed as a young cowboy. He haunts Danny everywhere he goes, planning to drive him crazy as he is the only one who can see him. This is because Youngblood cannot be seen by adults, or young people who have an adult mind like Jazz, as Youngblood is trapped in limbo among the children. Danny successfully manages to get Jazz to help defeat Youngblood by getting her to express her inner child, triggered by using childish insults, ripping her teddy bear, etc. As a result, Jazz is suddenly able to perceive the young ghost and join the fight against him.
Youngblood makes a cameo appearance in "The Fright Before Christmas" as one of the many ghosts who help Danny save Christmas. He makes another appearance, dressed up as an astronaut, in "Livin' Large" as he was preparing to hurl himself in the Ghost Zone. He joins Danny Phantom, Skulker and Johnny 13 in order to save both Earth and the Ghost Zone from The Guys In White. Afterwards, the three ghosts chase Danny away.
Youngblood's final appearance is in the series finale, "Phantom Planet". He is first seen terrorizing Casper High, again pretending to be a pirate, only to be subdued by Vlad's team of Ghost Hunters, Masters Blasters. Later, he is one of the many ghosts who help Danny and Skulker turn the entire planet intangible so that an asteroid can pass through it.
Youngblood is extremely carefree, sporty and not-so-surprisingly childish. He tries to act intelligent at times, but can't seem to hide his immaturity, but ironically enough, thinks people like Jazz should lighten up. He loves playing dress-up more than a game, and unlike Danny Phantom's other enemies has no desire for world domination, and is more for fun time. He seems to enjoy his eternal childhood, and he views adults as "party-poopers". He is also quite smart and is a natural leader, commanding a vast army of undead ghost pirates.
203. "Pirate Radio" 207. "The Fenton Menace" 307. "Livin' Large"