A male rookie caught it during his journey before Trade, Borrow, and Steal!.
Journeys[]
In Trade, Borrow, and Steal!, a Male Rookie traded Ekans for Ash’s Venonat. In A Crackling Raid Battle, Ekans attempted to use Wrap on a Zapdos, but it dodged the attack before it could land. In JN057, it befriends a Trainer’s Psyduck. In JN058, it got stuck in Gulpin’s Giant Ball, and tried to use Iron Tail to break free which failed. Ekans was also seen in JN062. In PJ068, Ekans had revealed to have learned Acid since its training.
In PJ072, He was able to utilize his Intimidate ability to weaken The Durant's attacks. He evolved into an Arbok and learned Thunder Fang in the process, which he managed to paralyze it.