Tanks a Lot!

Plot
A wild Sentret stumbles upon Ash and his friends, who are taking a daytime nap, and reports what it saw back to its fellow Sentret. Meanwhile, Team Rocket is testing out their new Arbotank, a tank resembling Arbok. Though Jessie finds the group sound asleep, Meowth points out that the noise from the Arbotank may wake them up, so Team Rocket contemplates merely getting out and walking in order to ambush them.

Later, the first Sentret returns and tries to figure out what Togepi is, but in the process, Togepi rolls down a hill, and it chases after it. At the bottom of the hill, Togepi wakes up and meets Sentret. The two play together and end up rolling off a cliff and into the Arbotank's hatch opening. Team Rocket hears the noise and is instantly alerted to the two Pokémon playing with the Arbotank's control panel. Togepi jumps on a lever, causing the mecha to take off, and Team Rocket chases after them.

Misty wakes up and notices that Togepi is gone, but before she can wake up Ash, another Sentret comes along and wakes him. It tries to desperately tell him something, and Brock suggests that it is trying to find something it has lost. Then, the trio hears a crash in the distance, revealed to be the Arbotank colliding into a cliff. Ash and his friends, meet up with Team Rocket, who tells Misty that Togepi and its Sentret are controlling the tank. Brock sends out Onix so the group can get to the tank faster. They arrive at a clearing that the Arbotank will be passing by and devise a plan to stop the Arbotank. The plan partially succeeds, allowing Pikachu to board the stuck Arbotank before it returns to a standing position and is freed.

While dressed as magicians, Team Rocket uses a magic trick to trap the Arbotank in another hole. Meowth jumps inside, only to be greeted with Pikachu's Thunder Shock. The shock causes a technical failure, which activates a spring on the bottom of the Arbotank, and the mecha bounces out of the hole. Ash, his friends, their Sentret, and Team Rocket give chase again as the Arbotank continues its rampage. At Ash's insistence, Sentret calls out for danger, allowing the other Pokémon to hide and reach safety. The tank starts going faster and is about to crash into the side of another cliff, but Togepi uses Metronome to drill a hole through the mountain. Brock realizes that if it drills straight through the mountain, it will destroy a town on the other side. As a result, Ash sends out Charizard to defeat it.

The group follows Charizard aboard Onix, just as Charizard is almost able to bring the tank to a halt. Pikachu, Onix and the group's Sentret helps Charizard, eventually causing a complete mechanical failure. Charizard then uses Flamethrower to melt one of the mecha's windows, allowing to Pikachu, Togepi, and their Sentret to flee. However, with Meowth still inside, Jessie and James try to rescue the Arbotank at the last second. However, the mecha explodes, sending them blasting off again.

As Ash and his friends watch the smoldering remains of the Arbotank, the two Sentret reunite while Misty scolds Togepi. Officer Jenny arrives on the scene in her motorcycle. She thanks Ash and his friends for creating the tunnel, which halves the time required to travel between the town and Violet City. The trio laughs amongst themselves about the fact that Team Rocket were responsible for some accidental good.