Octopus is the 1st episode of Season 3. Oggy befriends an octopus which the cockroaches want to eat. However Oggy does not know that this octopus makes a habit of plotting robberies – for example, when Oggy is at his most unaware while he is sleeping, the octopus evilly sniggers and pulls Oggy's stuff into his head.
Oggy is preparing sushi with the cooked rice, while the cockroaches are craving for them. He then pulls out a live octopus and attempts to slice its tentacles with a big knife. The octopus sorrowfully begs Oggy not to do it by balling out his eyes. Convinced, the latter then throws the knife back, hitting onto the cockroaches' rears, as if they were pants. The octopus thanks Oggy for his preservation by kissing him, as he then tickles the latter for gratitude, with the roaches looking dismayed.
While watching TV, the octopus serves Oggy with a meal of chicken from the fridge, apple from a tree, slices of bread toasted, and milk delivered. The cockroaches are watching them loafed, except for Dee Dee, who still hungers for the octopus' tentacles. So he pulls off a knife and a fork and chops off a tentacle above Oggy unnoticed by the latter. With his move, the roaches can eat the chopped tentacle, but were interrupted by the suckers by hitting their mouths. It then traces back to the octopus, who detected the roaches and reveals them to Oggy, The latter teases them while the former throws them out of the window. They celebrate this with numerous high fives.
At night, Oggy feels tired. So the octopus elevates him to his room, and tucks him in his bed, while also switching off the lamp beside them, putting the cat to sleep. In the bathroom, the cockroaches popped out of a faucet attempting their plan against the octopus, but he then suspects them with his tentacles, forcing them to run and hide somewhere. He detects at the sink, and finds them inside the toothpaste by squirting them out on a toothbrush. He then scrubs them inside the toilet, and flushes them. After that, he checks if Oggy is still asleep, and reveals his true colors. He steals every possible item inside the sleeping cat's house, hinting that he is actually a thief.
In the morning, the octopus prepares by exercising, taking a shower, and grooming, while Oggy is idled below him. At a supermarket named Hyper Mega, the two shops for groceries. The octopus then buys two meat parts; weighed apples for price, interrupting another customer who chagrined; and beats up a seafood vendor for selling octopus by his head.
Arriving at home after shopping, they rest in front of the TV with the octopus massaging Oggy on his cheeks. The cockroaches came out in a lampshade, but octopus then flips the switch, shocking the roaches to dust. He then sweeps them and throws them out the trash. While massaging Oggy, he continues to steals more items in the cat's house unsuspected. An unrequested delivery then came. so he accepts the package while also kicking the deliveryman off. He checks it for inspection, as it reveals inside to be the roaches frightened at his act. So he wraps up the package like a gift, and delivers it to another neighbor, Bob. The dog was satisfied with this "gift", so he open it, revealing the roaches. Dismayed, he beats them up with a broom repeatedly.
As Oggy fell asleep, the octopus then steals the remaining items, and leaves the cat apathetically. But, as he opens the door, Jack suddenly arrives. The latter then punches the former. He brings the knocked out octopus to Oggy for a meal. The latter then worries about the octopus being served, so he negates. They fought over this, until a sudden rumble was heard. Jack then squeezes the head of the octopus, raining out all the items the latter stole, and revealing his true nature in front of Oggy. Realizing this, the latter cries heartbroken. Jack throws the octopus, as the latter escapes. He was interrupted by the roaches from crushing him with the pillars, preparing him for a meal. However, he finally escapes by an oncoming Volkswagen Beetle despite detaching one of his tentacles inadvertently. The cockroaches were disgruntled by this, but Dee Dee notices the detached tentacle left behind, finally getting what they want from earlier.
Oggy finally serves the octopus sushi to Jack and the roaches. Dee Dee then attempts to eat one of them, but was interrupted again by one of its suckers, hitting his face. The chopped tentacles then escape from being eaten to their host, as the cats and the cockroaches chase them.