In the original 151 Pokemons, Psyduck and Slowpoke are the two “derpy-looking” Water/Psychic types. Psyduck has mystical powers, but doesn’t recall using them; which is why it always looks so confused. Meanwhile, Slowpoke is so oblivious that if something bites its tail, it won’t even notice for a whole day. In episode 66 of the anime, when the team is tasked by Oak to figure out what causes the evolution of Slowpoke to Slowbro, Misty’s Psyduck comes out of it’s Pokeball and proceed to have a long, seemingly random and unintelligible conversation with a Slowpoke.
Correction
Um actually … Psyduck is not a Water/Psychic type, it is a pure Water type despite it’s namesake.
(The Japanese name of Psyduck was Ko-duck, which could mean “child-duck” and thus does not hint at its psychic abilities at all)