This Pokémon is a coward. As it desperately dashes off, the flailing of its many legs leaves a sparkling clean path in its wake.
– Pokémon Sun Pokédex
Wimpod is kind of like the Magikarp of Gen 7; it doesn’t learn any moves via level-up (and only knows Struggle Bug and Sand Attack). It’s kind of unique in that it can be encountered via over-world sprites, and they’ll run away from you, so you’d have to sneak up on it in order to get an encounter.
Wimpod has a unique ability in Wimp Out, which will make it switch out (or flee in wild battle) when below 50% HP, which means quick balls are the best way to catch wild Wimpods.
Stat-wise, it’s pretty fast, but its other stats are all pretty low.