Jynx, the Human Shape Pokémon. Jynx is a unique Pokémon because it’s an Ice/ Psychic type. Here’s a little bit about Jynx in Pokémon Red, Blue, and Yellow Versions.
Jynx can only be found in Red and Blue. To get one, you have to trade a Poliwhirl to a guy in building to the left of the Pokémon Center in Cerulean City. It will be nicknamed “LOLA” and the only way to get one named something else is to trade one or catch one in Gold, Silver or Crystal, breed it, then raise the Smoochum to level 30, evolve it and trade it back.
Since the person that’s in that house in Yellow gives you Bulbasaur instead, you can’t get a Jynx in Yellow without trading. More on how to get Bulbasaur in Yellow
Jynx is pretty powerful, considering it learns both Ice and Psychic moves, including Blizzard, Ice Punch, and you can teach it Psychic or some other good TMs as well.