There are lots of different kinds of trucks, but only one that can turn into a giant robot - Humunga-Truck! The Bubble Guppies learn all about different kinds of trucks on their way to the big Truck Show!
A loud honking noise interrupts Molly when she tries to introduce the show. On her third try, a large truck reverses behind her. The window winds down to reveal the driver - Gil! He sounds his horn one last time and shouts: “It’s time for Bubble Guppies!”
Molly and Gil are on their way to school when they notice a truck, stuck in some sand. The driver has called a tow truck, which soon arrives. Frank, the tow truck driver, shows Molly and Gil how he rescues vehicles by attaching a hook and pulling the truck free. It’s not long before someone else needs Frank’s help, so he says goodbye and drives away.
When Molly and Gil get to school, they tell everyone else about the tow truck. Soon all of the guppies are talking about their favourite kinds of truck, including fire trucks, garbage trucks and even ice cream trucks. This inspires the guppies to sing Trucks are Tough!
After the song, Deema pretends that she has a huge shipment of toy trucks to load onto an actual truck, which Gil is driving. Gil‘s truck, however, already has a lot of boxes inside, not leaving much room for Deema’s shipment. Gil, however, is sure he can fit them all inside. With help from the viewer, Gil finds the right size gaps for the boxes to fit inside, including filling one rectangular gap with two square boxes. Mr. Grouper then announces that it’s lunch time.
After lunch, Gil is hunting for an ice cream truck. He hears a reversing noise and finds the truck that’s making it – A fire truck. Gil, however, thinks it’s an ice cream truck! He points the water hose at himself, expecting ice cream to spray out, but instead gets blasted off screen with a jet of water! Goby arrives and invites everyone to play trucks. In the classroom, everyone is busy playing with toy trucks. Mr. Grouper announces that he’s taking them to a truck show, where lots of different trucks will be, including Humunga-Truck – A huge truck that can turn into a robot! It’s then time to go outside.
Oona and Nonny are truck drivers, who are hauling a special delivery of unicorns to Rainbow Mountain. On their drive, Nonny becomes worried and Oona asks him what the matter is. Nonny is concerned about the huge monster truck which seems to be following them. When the truck shouts ‘Hey!’ at them, Oona and Nonny panic and speed away from it. The monster truck doesn’t stop chasing them, and Oona decides to go off road. Although they lose the monster truck, they end up getting a flat tyre. To change the tyre, Oona and Nonny need to choose the right replacement – A tyre with a pentagon shape. With the viewer’s help, they pick the right tyre and head straight to Rainbow Mountain. The monster truck catches up with them, but reveals that he was just trying to deliver hay for their unicorns. As it turns out, he was shouting ‘Hay!’ instead of ‘Hey!’. With the story complete, Goby invites everyone to do the Hands on the Wheel dance!
After the dance, Gil is still looking for an ice cream truck. A truck shows up, but it’s definitely not an ice cream truck. Gil, however, is determined that it is and pulls a lever. The truck turns out to be a garbage truck, and buries Gil under a mountain of trash! It’s then time to go to the truck show!
The truck show is held in a massive stadium, where trucks of all types drive in and out as the crowd cheers. Deema rides in a garbage truck, Goby rides in a fire truck, and Oona and Nonny get to stand in an ice cream truck. Soon Humanga-Truck storms into the stadium, but quickly gets stuck in some wet sand, which was caused by the fire trucks. Frank, Molly and Gil ride over in a tow truck, which soon frees the Humunga-Truck from the sand. The crowd cheers as Humunga-Truck transforms into a giant robot and dances to a reprise of Trucks are Tough!
Before the show ends, Gil finally finds an ice cream truck, which he says is full of his favourite flavour ice cream. He turns out to be right, as the whole truck is literally filled to the brim with ice cream, which pours all over Gil when he opens the back of the truck! Everyone laughs as the show ends.
Strangely, at the end during the truck show, the tow truck is able to get Humunga-Truck out of the mud, even though the tow truck is much smaller than Humunga-Truck, it would be impossible to get a truck out of the mud in real life when using a tow truck.
In the episode that came before this one, "Tooth on the Looth!" Deema loses a tooth. Strangely, in this episode, Deema does not have a gap in her teeth, where the tooth used to be. Although it's possible that her adult tooth already grew in.
When Mr. Grouper says it's time to go outside, Goby is wearing a trucker's hat, but when the Bubble Guppies line up, Goby's trucker's hat is gone.