It lives hidden within thicket shadows. When predators attack, it quickly bristles the fur covering its body in an effort to threaten them.
The beaks of birds can't begin to scratch its stalwart body. To defend itself, it spews powder.
Spewpa is the first cacoon Pokémon that is the same size as its pre-evolution, Scatterbug.
Spewpa is most likely derived from the word "spew" and "pupa". The "spew" references the "spewing" of insects, and "pupa" because it is in a shell-like form, as well as being evolved from Scatterbug and the pre-evolution of Vivillon.