Cow and Chicken get an unexpected visit from Cow's twin cousin, Sow (a pig with 8 teets). After Sow's first day at school, she causes chaos, and puts the blame on Cow. It's up to Cow to pull the plug on Sow's evil ways.

Cow brings home an ""invisible"" dog, whom she dubs, Kevin. Pretty soon, she and Kevin are inseperable, but causes trouble with school and friends. After she enters Kevin in a dog show, and wins, Kevin ""runs away"". Afterwards, Cow finds Kevin, befriended an ""invisible"" homeless man.

Weasel creates a time machine that I.R. uses to go back in time, but Weasel discovers that I.R. is destined to solve all kind of problems at certain periods.

Cow is depressed because she has no friends: until she finds a fly in her room and befriends it. Pretty soon she and the fly are inseperable: until Chicken, Mom and Dad call in the fly exterminator.

The Red Guy is depressed because no one will play with him. After seeing Cow has Crabs the Warthog, he wants to play with her because he has Crabs's doll house. When he askes to play with Cow, she tells him not if he was the last man on earth. With that he locks the entire world in a trailer, and is the last man standing: but Cow still won't play with him.

Weasel comes to investigate the world's largest hole, same hole I.R. tries to fill with cement.

Weasel is the captain of his own comercial plane, and must take a bunch of people up a river with I.R. as his co-pilot.

Mom and Dad go out of town, leaving Cow as the babysitter, because she's the biggest, and not the oldest. Pretty soon, Chicken is at the mercy of his sister's babysitting technique: eating marshmallow soup for supper, doing homework with Crabs the Warthog doll, Piles the Beaver doll, and Manure the Bear doll, taking a bath and being scrubbed with dishsoap, and wearing diapers.

Weasel and I.R. are sent to a correctional institute were everyone is forced to wear stupid corrective devices.

After Earl gets the new Sergeant Weenie Arms action figure, he, Flem and Chicken go to Dead Skull Cave to meet the soldier himself, and become full-fledge weenie marines. After they do so, they learn that weenie marines are sissies.

Cow has a crush on Crag, the smartest kid in school, but is ignored by him. Her friends try to convince her that her horns are too small, so she tries every way to make them bigger by decorating them with coat hangers, paper masche, and even chocolate chip weenies. Cow later learns that Crag wasn't interest in Cow, because he had a crush on one of her friends.

Cow stays outside too late, and pretty soon finds herself lost in the woods, and tries to survive. She pretty soon comes to the conclusion that it's eat, or be eaten, so she puts on war paint, and finds a squirrel in a bush, she quickly eats. It turns out she was in the backyard all the time, and her imagination got the better of her.

While driving in the snow, Mom and Dad find The Red Guy who says he's heading ""home""; so Mom and Dad take him home with him, and immediately think of him has their new favorite son. Cow and Chicken work together to try to prove The Red Guy's a fraud.

Cow tags along with Chicken, Flem, and Earl on their camping trip in the tree fort. Cow says that if Chicken, Flem, or Earl touch her dream catcher that they'll die. Chicken accidentally breaks her dream catcher, and soon, he, Flem and Earl are at the mercy of Cow's worst nightmare: The Milkman.

Weasel and I.R. end up stranded on an island made entirely of confectionaries.

Grandma pays at visit to Cow and Chicken's house to take them to the mall with her. Her purpose for being at the mall: to look for a new grandpa, because she lost the old one. Chicken gives her the slip while he, Flem and Earl hang out at the concession stands.

Chicken refuses to take bath, so he just sits there in the empty tub, while Cow, Mom, and Dad try to make him take a bath so they can use the toilet.

I.R. is captain of his own ship, until it bumps an iceberg and it starts sinking.

Cow and Chicken are taking a trip all by themselves. Their taking an airplane. Once Chicken sees the actual plain, he starts to have anxiety attacks and believes that flying is a dangerous way to travel.

P.E. Chicken, Flem, and Earl are finally 6th graders, and are ready for their first day at junior high. Once in their gym class they find it difficult to put up with a strict P.E. teacher, and bully twins.

Weasel and Baboon are a pair of friendly vampires who drink only canned blood and are just looking for a fun little night on the town in Pantsylvania. But someone should try telling that to the vampire hunter Dr. von Smellstein, who's out to get our heroes!

Cow and Chicken have a big test the next day at school but when Chicken forgets to study, he tries to fake all kinds of illnesses to avoid going to school. After holding his thermometer over the grill, Mom and Dad call the doctor who makes housecalls: The Red Guy.

Chicken is upset because he can't whistle, and everybody else can. The Red Guy tries to tutor Chicken, but he finds out that Chicken can't whistle because he has no lips. The Red Guy then immedietaly sends Chicken to surgery.

I.R. is jealous of his neighbor Weasel because he has a better wife, kids job and house than him.

Cow wonders about the day she was born. Chicken tells her she was adopted, Mom tells her that the stork delivered her, Dad said they found her in a cabbage, Teacher says she hatched from an egg, and Red Guy says he delivered her.