These two are Priscilla Pluto’s parents, Perseu Pluto and Pollyana Pluto!
She prefers that people call her Polly, though.
They’re a couple of space adventurers who go on SCIENTIFIC OUTER SPACE ADVENTURES!
Perseu is a biologist and geologist, his peers nicknamed him “The Punching Scientist” for his physique and "very enthusiastic hands on” aproach to reaserching and cataloging new specimens (which may or may not involve hi-tech laser brass knuckles).
Polly, his wife and assistant, while not an scientist herself, is a very powerful Esper (an individual with psychic powers), one of the strongest registered by the PResLabs (Psychic Research Laboratories). With her bubbly personality and positive attitude, she can destroy small planets.
Together, they were relatively suscessful and even saved the Galaxy they resided a few times and the universe once!
Sadly, they disappeared when Priscilla and her sister were 16 years old on said universe-saving adventure, when they managed to trap a mathematically impossible creature on a place outside of the fabric of reality.