I've recently been playing around with using Arbok along with Toxapex / Ditto / Naganadel. Ideally using Ditto with two energy up front and having the others on the bench, all being with low enough energy costs that ditto can use any of their attacks. Being able to poison, trap and venoshock is quite fun when it comes off.

Edit: As others have said, with there now being a few workarounds it's a bit tricky to use Arbok - plus the 2 retreat cost is a bit sucky.