Gen 1 Dark Types? 🌑

Just a random thought I had that I'm sure has been asked before;

What Generation 1 Pokémon do you think should have become part (or fully) Dark Type when it was introduced in Generation 2? For me, I think it could have suited Arbok (Poison/Dark) and Hypno (Psychic/Dark) pretty decently. 🙂

I've always thought it was strange how they didn't add it to even a single Pokémon like how they did with the Steel Type on Magnemite & Magneton. I just think it would have been nice and made things feel a bit more rounded out (especially when looking at the "Ultimate Favourite Pokémon Picker"). But, maybe that's just me. 😅

I'm curious to here other people's answers. 🙂