The Grim Adventures of Billy & Mandy (season 3)

Super Zero: After watching a TV show, starring Captain Space Heifer and his Heifer Farms Brand Yogurt, Billy asks Grim to turn him into a superhero with the power of squeaking and throwing yogurt from his armpits. With his wish granted, Billy goes to outer space to fight the Evil Empire, but the planet he visits is inhabited except for an adorable little alien creature whom Billy fails to notice almost the entire episode and is smothered in Billy's limitless supply of armpit yogurt. Despite being free of Billy, Grim still has to deal with Billy's equally dumb father, Harold. After Billy fills the alien planet with yogurt, he returns home to be "normal".

Note: There is also a The Fairly OddParents episode that also called "Super Zero".

Bearded Billy: When Billy sees his father, Harold shaving, he decides having a beard is cool and buys "Hair Raiser Tonique", a hair-growing formula. Grim casts a spell on the tonic to make its effects appear faster, but Billy exaggerates the quantity and grows hair in all over his entire body. Billy is mistaken for the Sasquatch and a reward is offered for his capture. Hoss Delgado also receives the tonic and is captured and exhibited as the Sasquatch, while Mandy collects the reward.

Test of Time: When Billy forgets to do his history homework, Grim gives him a universal remote control to alter time and space so he can go back in time and finish his report. Billy and Mandy travel to the American Revolution, to prehistoric times, and even to the future, where they meet an aged Billy who is just finishing the report. After a struggle for the remote, Billy ends up again in the prehistory and the remote breaks. Fast forward into the present, every person is dumb and slowwitted just like he is and shares his characteristic "dot eyes", big nose and laugh, including Mandy and Irwin.

A Kick in the Asgard: During a thunderstorm, a lightning bolt hits Grim's scythe, transporting Billy to Asgard, land of the Norse gods. Mandy and Grim go searching for him, while a Viking wearing Billy's shirt remains at his house as a substitute. In Asgard, Billy learns about the endless battle in Valhalla, in which if a warrior dies, he is resurrected to continue fighting. Billy is surprisingly good at killing other Vikings, so Mandy and Grim are unable to convince him to return home.

Attack of the Clowns: After Billy wakes up from another nightmare involving clowns, he is more terrified than ever towards them, so Mandy and Grim try to cure him of this clown-a-phobia. Mandy asks Grim to bring to life a clown's head made on paper mache to entertain Billy, but the spell does not seem to work. They dress up as clowns in an attempt to look harmless. After consulting with his imaginary "Inner Frat Boy", Billy changes his feeling from being afraid to being angry at clowns, and attacks them with Grim's scythe. Billy is cured of his fear, but the paper mache clown attacks and eats them and they all hate clowns in the end.

Complete and Utter Chaos (Billy Gets Dumber): Thinking that the world is chaotic enough as it is, Eris, the goddess of chaos, decides to quit chaos to work at a hamburger restaurant. She entrusts Grim the Apple of Discord to watch over for her, which he seals in his old trunk. The apple frees itself from the chest and goes to Billy. Mandy is attracted by the apple's powers, and after being persuaded by Billy's talking burrito, Billy, Mandy and Grim battle for control of the apple, which divides in three pieces. The battle results in them being fused together into an amorphous mass and, with an evil grin on her face, Eris decides to offer the apple to Irwin too.

Whatever Happened to Billy Whatishisname?: When Billy and Mandy have a brief fight, Billy says he never wants to speak to Mandy again. The next day, Billy is over his grudge, but Mandy has already decided to find a replacement for him. Mandy introduces Bobby, the new "Billy" replacement, who turns out to be a better friend than Billy, even gaining the affection of his parents, but who also wants to take over Billy's life. A jealous Billy uses Grim's scythe to open a portal and send Bobby to another dimension.

Chocolate Sailor: While reading an Underworld comic book, Billy finds an advertisement for "Chocolate Sailors", a delicious chocolate candy-which being Underworld candies are secretly hexed into enslaving the eater. Billy becomes a seller of Chocolate Sailors, but instead of selling them ends up eating them all by himself. The enchanted candies turn him into solid chocolate, and now Billy cannot stop eating himself. Billy, Mandy, and Grim go searching for the Chocolate Sailor to retrieve the antidote before Billy eats himself completely. Instead of eating the antidote, Billy eats the antidote along with other enchanted chocolates, and his head (which was all that was left of him) explodes as a result and covers Chocolate Sailor, Grim and Mandy in chocolate. Later Grim and Mandy are shown watching TV while drinking "Billy" Chocolate shakes. On one of the "Billy" Chocolate shakes bottles, the Billy Sailor on it says, "I like chocolate".

Toys Will Be Toys: Thanks to Mandy, Billy decides to get rid of his "Dinobonoid" action figures thinking he is too old for them. Grim makes the toys come to life, and shrinks Billy to their size so he can have a last adventure with them. The "Jurassic Creeps" become aware of Grim's scythe and steal it from him to use its powers to rule the world; however, the magic that made them come alive runs out just in time, and the toys become inanimate once again. Billy reverts to his normal size too, but he stays trapped inside the box in which the action figures came.

At school, Billy, Mandy, and Irwin look for a club to join. Irwin plans to join the Macrame club to meet girls; Billy inquires on the Junior CIA club, which forcefully recruits him; Mandy joins the "Secret Snake Club", a snake-themed club consisting of three geeks. The nerds reveal that their "secret agenda" is to resurrect Shnissugah, a giant snake which lived hundreds of years ago in Canada, to take revenge against the popular kids, but they lack the power of the Underworld to do so. Mandy calls for Grim, who proceeds to revive Shnissugah through the internet, even though the geeks tie her up using their pet garden snake, Wiggly Jr. Billy, as a junior agent of the CIA, stops a criminal plan by Irwin, who was using the Macrame club for personal gain; and Shnissugah turns out to be a tiny, 8-cm (3.14-in) long, harmless snake who forces the nerds to untie Mandy and goes back into the internet. Mandy ends up beating up the three geeks severely.

He's Not Dead, He's My Mascot: When Billy and Mandy's school is preparing for a big game, Mindy entrusts the care of the school's mascot, Fluffy Cat, to Billy, to protect him from being kidnapped by the rival team, the Booty Heads. At Billy's house, Fluffy Cat is a disaster, so Billy's mom throws him into the basement, where the cat gets inside Grim's trunk, absorbing its powers. A giant Fluffy Cat appears just before the game wreaking havoc and spitting out a furious Mandy who says, "This is why I hate cats".

The Bad News Ghouls: After Billy's baseball team loses badly against Mindy's, Grim decides to coach them. Mandy is not allowed on the team, as Billy is reluctant to let girls play, although he does not realize Mindy is a girl too. Mandy puts on a baseball cap and, assuming the role of "Manfred", pitches for Billy's team anyway. With additional help from ghoulish players which played in the Underworld Little Leagues alongside Grim, Billy's team wins when Pud'n hits a home run. Pud'n ends up being lifted up by the other baseball players in celebration, but ends up crying thinking that they were going to hurt him.

Happy Huggy Stuffy Bears: After a trip to the mall, Mandy becomes the spokesperson for Happy Huggy Stuffy Bears, a new stuffed toy in town. After the success of her commercial, Mandy gives away stuffed bears, which were her payment from the commercial, to the other children in the neighborhood, who start wreaking havoc in the city. Eris, the goddess of chaos, is behind the toys, which mind-control the children into creating chaos. Mandy decides not to share control of the world with Eris, and orders Grim to destroy the toys, which he does.

Wild Parts: One night a strange odor travels through the city, prompting the noses of all the people, including Billy's, to follow it. The next night, Mandy, who is noseless, and Grim decide to wait outside Billy's house for the event to repeat. When the odor reappears, the nose parade leads them to the shopping mall, where they meet a "Nasalmancer", a nose wizard who is trying to take over other people's noses since he lost his own. Billy recovers his nose, but slices it in two, and gives one half to the Nasalmancer.

After Grim's robe comes out of the washing machine, Billy and Mandy find Thromnambular, a talking skull with ruby eyes and a number nine imprinted on his forehead. Grim tells them that the skull is a magical artifact imprisoned on Earth that must grant his nine wishes to be free. When Mandy asks Grim why he has not used any of the wishes, Grim tells her that the skull will corrupt the wishes and end up affecting the wisher. Despite this, Billy runs away with the skull and makes the first wish: (1) he wishes to be in an adventure (which parodies Indiana Jones and Jonny Quest), this backfires because Irwin is eaten, which Billy complains about getting him in trouble. After this, Thromnambular is found by different people who each make a wish: (2) Billy's dad wishes he could relive his high school years, but this backfires because he is not popular; (3) General Skarr wishes to rule on high, but this backfires because he asphyxiates in space; (4) Irwin (despite being eaten already in an earlier episode) wishes he was in a hip-hop music video, but backfires because he gets punched by Mandy; (5) Pud'n wishes he had a bunny, but backfires because he is almost killed by it, because "Sometimes Love Hurts"; (6) Nergal Junior wastes his wish by wishing for a wish that wouldn't backfire; (7) Sperg wishes for a way to get into the girls restroom to bully a girl into giving him a large sack of money, this backfires because he is turned into girl and insulted by the other girls for being ugly; (8) Mindy wishes to be a "big star", but this backfires when she is sent into space strapped to a rocket; (9) finally, Mandy tries to auction the last wish, but Grim gets ahead and wishes the kids never found the skull in the first place. This goes back to the beginning of the episode where Billy is staring at the washing machine, followed by Mandy pushing him into it.