It aired from 1996 to 1998 and lasted for two seasons.
- Adaptational Dumbass: The Wickershams tend to be portrayed as clumsy louts who talk in Hulk Speak.
- Art Evolution: While the entire series used a "digital backlot" with the puppets performing in front of a green screen and a CGI set, the second season had the Cat's playroom as the only live-action set.
- Ascended Extra: Quite a few characters, including the Little Cats (who appeared in The Cat In The Hat Comes Back), and Morton the Elephant Bird (who appeared without a name at the end of Horton Hatches the Egg).
- Beware the Nice Ones: The Cat in the Hat is a very warm hearted main host, but does still have shades of his trickster personality, "Yertle the King" being one of the best example.
- Big Storm Episode: In "There is Nothing to Fear in Here", The Cat in the Hat, the Little Cats, and Terrence McBird take shelter in the Cat's Playhouse when a thunderstorm causes the lights to go out. Terrence is afraid of thunderstorms, but the cats help him overcome his fear by inventing in-the-dark games.
- Birthday Episode:
- In "The Birthday Moose", it's Thidwick's birthday, and Thidwick is excited about the Birthday Bird taking him and his friends sharing the same birthday, Morton the Elephant Bird, Mr. Knox, Fox in Socks, and Fiona Phish, to Katroo for a huge party. When Thidwick finds out that the Birthday Bird is unable to make it this year, he decides to take him and his friends to Katroo himself, disguised as the Birthday Bird.
- In "The Cat in the Hat's Big Birthday Surprise", it's Terrence McBird's birthday, and he thinks his friends have forgotten. They're really planning his surprise party. In the Wubbulous World, Felix Finkledooper celebrates an extra-special 8th birthday with the 8th Birthday Glurk, and Princess Tizz is sad because all of her birthday presents are too rare and precious to play with.
- Canon Foreigner: While many of the characters on the show are pre-existing Dr. Seuss characters, others were created specifically for the series. Two of the most notable are Sarah Hall-Small and Terrence McBird, both of whom debuted in the second season.
- Clear My Name: The episode "The Snoozer".
- The Complainer Is Always Wrong: This was the A-plot for many of the episodes of the second season. Usually, the Cat in the Hat and the Little Cats will engage in some kind of fun activity, but Terrence McBird will refuse to try it at first. When he does finally join in the fun activity towards the end of the episode, he finds out he actually had fun and it wasn't as bad as he thought it would be.
- Did You Die?: The episode, "Norval the Great" features Binky telling his friends about his adventures with his pet fish, Norval. In the middle of the story, one of his friends asks, "Did you and Norval die?". The others look at her and respond, "Duh...".
- Distaff Counterpart: The second season introduces Pam-I-Am, the female counterpart of Sam-I-Am (who also debuts in the same season).
- Egg MacGuffin: The episode, "The Song of the Zubble-Wump" involves a girl named Megan and her friend Horton the Elephant trying to retrieve the priceless Zubble-Wump egg, which was stolen by The Grinch.
- Evil Chancellor: In "The King's Beard", Yertle the Turtle acts as the trusted advisor for two different kings.
- Fear of Thunder: In "There is Nothing to Fear in Here", Terrence McBird is revealed to be afraid of thunderstorms, especially ones that cause the lights to go out. The Cat in the Hat and the Little Cats help him overcome his fear by inventing in-the-dark games.
- For Want of a Nail: In "The Mystery of Winna-Bango Falls," Jane Kangaroo's efforts to keep the inhabitants of Lake Winna-Bango from littering their Fruzzle Floom Fruit peels causes a whole chain reaction that stops the Winna-Bango waterfall from flowing.
- Friendly Neighborhood Spider: In "A Bird's Guide to Health", Horton meets Sid the Spider, a spider whose left legs were crushed by a fallen tree. Despite Horton's initial fear of spiders, he and Sid become friends. Horton nurses Sid back to health, but is harassed by Jane Kangaroo and the Wickershams, who all think that bugs are creepy and not friendly. Sid, not wanting to cause trouble for Horton, sweetly says his goodbyes, causing a Heel Realisation from Jane.
- Hiccup Hijinks: In "The Sounds All Around", Terrence McBird gets a case of the hiccups. At the end of the episode, Terrence follows Pam-I-Am's advice to take slow, deep breaths, and this cures him.
- Infant Sibling Jealousy: In "Lester Leaps In", Sarah Hall-Small becomes jealous of her new little brother, Paul, because of how much time her parents spend with him, and how they hardly pay attention to her anymore. Whenever they do, it's usually to remind her to be considerate of him, such as not playing her big bass thumper bumper too loud when he's trying to sleep. Sarah eventually gets the idea of acting like a baby herself to get her parents' attention, until her parents tell her that they'll always love both her and Paul equally. Upon hearing this, Sarah changes her attitude about Paul and promises him that she'll be the best big sister ever.
- Inventional Wisdom: In "The Muckster", Jane orders the titular invention to help her clean her messy house for her appearance on The House and Home Show, with specific instructions from the Cat in the Hat and the Little Cats never to turn the dial to 6. When Jane is tempted to turn the dial to 6, Junior reminds her not to do so, to which Jane questions why the Cats would put a 6 on the machine to begin with.
- Jerkass: The Grinch and Yertle expectedly take the role of antagonists, though with Pet the Dog moments here and there.
- Jerk with a Heart of Gold: Jane Kangaroo can be overbearing and close minded like her book counterpart, but does care about her son and sometimes feels bad when she crosses the line.
- Massive Multiplayer Crossover: Many of the characters from many of Dr. Seuss' works combine to form the series' adventures. Notably, The Cat in the Hat is the show's host, and The Grinch and Yertle the Turtle are the series' recurring villains.
- Minsky Pickup: Done at the beginning of the Fox and Knox intro.
- Mythology Gag: The sour kangaroo and her joey from Horton Hears A Who are named Jane and Junior, as they were in Chuck Jones' Animated Adaptation.
- Named by the Adaptation: The elephant bird who appears at the end of Horton Hatches the Egg is named "Morton" in the series.
- No Fourth Wall: Mostly used in season 2.
- Not on the List: In "Horton Has a Hit", Morton is trying to get into the theater where his father, Horton, is performing, to stop a World Tour that Yertle the Turtle is planning to take him on afterwards. The security guard refuses to let him in, telling him he's not on the guest list. Morton asks him who is, and he checks his list and tells him, "Everyone except Morton the Elephant Bird". Upon hearing this, Morton leaves, then comes back in a Coat Hat and Mask disguise so the Security Guard will let him in.
- Passing the Torch: In "Mrs. Zabarelli's Holiday Baton", after directing the Jingle Day pageant for 49 years, Mrs. Zabarelli retires and gives the job and her baton to her prize student, Annie DeLoo. The episode ends in the future, with an elderly Annie passing the job and the baton to her prize student, Arianna.
- Picky Eater: In "The Feed You Need", Terrence McBird refused to eat birdseed brickle in any color other than red. He eventually tried both pink and blue birdseed brickle near the end of the episode and found out it wasn't as bad as he thought it would be.
- Picnic Episode: In "The Cat in the Hat's Indoor Picnic", rain spoils plans for an outdoor picnic, much to the dismay of Terrence McBird, who was looking forward to playing in the sandbox. The Cat in the Hat and the Little Cats improvise by spending their picnic in the Cat's Playhouse, and making a sandbox for Terrence with his birdbath and dried corn. In the Wubbulous World, Princess Tizz imagines where the most special picnic spot could be.
- Put on a Bus: Thidwick the Big Hearted Moose only appeared in the first season.
- Retool: The second season boasted a Two Shorts format, with a sub-plot involving The Cat in the Hat and the little cats from the second book serving as a Framing Device for each episode. The theme song and several performers/puppeteers were also replaced.
- Rhymes on a Dime: Not consistently, but given the books they're based on, more than a little rhyming peppers the dialogue.
- Sick Episode: In "A Bird's Guide to Health", Little Cat Z gets sick, and Terrence McBird is afraid he'll catch his cold. It's up to the Cat in the Hat and the Little Cats to show him how to stay healthy.
- Sleep Aesop: In "The Cat in the Hat Takes a Nap", Terrence McBird is a bit cranky, so the Cat suggests he take a nap. Terrence initially refuses as he is a bird and it's cats who are known for sleeping a lot, but with the help from the Cat in the Hat and the Little Cats, he learns the importance of taking a nap. In the Wubbulous World, we get to see everyone's dreams and meet the Yapper-Nap, a creature who looks scary but turns out to just be tired, so Sarah Hall-Small sings a lullaby to help him sleep.
- Small Name, Big Ego: Keeping with his book, Yertle the Turtle is obsessed with power plays.
- Spiking the Camera: The characters tend to do this a lot, especially in the second season.
- Stock Footage: The ending sequence of the Cat singing "Let's Shout Hooray" in almost every episode of season 2.
- Speaking of season 2, we also get stock footage of the Wubbulascope cranking up and a transition from the Cat's playroom to the setting of the story.
- Super OCD: Jane Kangaroo tends to do a lot things on a strict regiment, even lullabying her son to sleep.
- Those Two Guys: Fox in Socks and Mr. Knox, who work together as a comedy duo.Fox: I'm Mr. Knox.Knox: I'm Mr. Knox!Fox: You're Fox in Socks.Knox: You're Fox in Socks!Fox and Knox: Yes, we are Fox and Knox!
- Trademark Favorite Food: Terrence McBird loves red birdseed brickle, as revealed in "The Feed You need".
- Turn the Other Cheek: One episode revolves around a young boy named Larry Nooly, who's dragged along to a hotel by his parents who are on their second honeymoon. He attempts to enjoy himself, except that the Grinch is also a guest and goes out of his way to sabotage everyone's fun, especially Larry's. Larry gets an idea at the end however, and has all the guests throw a surprise party in the Grinch's honor, and tops it off by giving him a gift. Unable to handle people being nice to him, the Grinch leaves.
- Unsuccessful Pet Adoption: In the first episode, "The Gink", Eliza Jane wants to keep a Gink (which is a cross between a Gunk and a skink) as a pet. The Cat in the Hat sings to her to adopt a different sort of pet because although Ginks can be pets, they require a lot of attention. When Eliza adopts a pet, she becomes too busy for her friends and eventually, the Gink grows homesick, so she puts him in the jungle but promises to visit him.
- Who's on First?: In "Horton Has a Hit", Fox in Socks and Mr. Knox do this kind of routine with Cindy Lou Who.
- Wrap-Up Song: Each episode from the second season ends with "Just Shout Hooray!", a song sung by the Cat in the Hat, telling the viewers to come back next time for more fun with him. In some episodes, the Cat is accompanied by the Little Cats and Terrence McBirdHooray for us,
Hooray I say,
Hooray for all the fun that we have every day,
And all the new faces and all the new places we see,
Just you and me!
So come back soon, and when you do,
I'll have some new surprises in my hat for you!
Just one last thing, and then I'm (we're) on my (our) way,
Let's shout hooray!
Just shout hooray!
- You Mean "Xmas": Jingle Day in "Mrs Zabarelli's Holiday Baton".