Arbok

Arbok — Released Jessie's Pokémon.

The Beginning
In S1E2, Pokémon Emergency, it appears as Ekans. Team Rocket send out it and Koffing, while attacking the PokéCenter and recited their Motto. During attack they were attacked by overpowered Ash's Pikachu and blasted off, after this they were determined to chase it.

Team Rocket send them out again in S1E3, Ash Catches a Pokémon, to battle Ash again, but Ash's Caterpie used String Shot and made them unable to move, Team Rocket said that they are blasting off, but, they'll be back and ran away, leaving the red rose behind.

They were used by Team Rocket in S1E6, Clefairy and the Moon Stone, where they battle Ash and friends, but lost and blasted off. They've fought againist Ash and friend again, when Team Rocket tried to steal the giant Moon Stone. During the battle James' Koffing used Smoke Screen and Team Rocket succesfully stolen the Moon Stone with underground path, Ekans made. Team Rocket escaped from there and were seen riding a Transport Sleigh with Moon Stone on it, they thought, that mission is complete, but Brock's Onix unexpectedly appeared on their way from underground, causing them to fall down. James tried to fight him with Koffing but both fainted as a result, then, many Clefairy appeared from underground and attacked them with Metronome, causing a big explosion. In the end Team Rocket blasted off for first time using their catchphraze, "Well, it looks like Team Rocket... Blasting off again..." after this twinkle appeared.

In S1E8, The Path to the Pokémon League, they were used alongside Meowth to battle AJ in his Gym, but they lost and escaped.