It evolves into Fevira starting at level 28, which evolves into Fevesta starting at level 42.
Feva uses its hair strands to sense soundwaves in the air, so as to locate other Pokemon; specifically its species. Feva can also not only cause sicknesses, it can cure people as well with the right motives.
Feva can make any human or Pokémon fall ill, simply from contact alone. Specialized gloves are sold in stores for handling of the evolution line.