I've seen so many avatars where I wondered what they were from, so I thought we'd all just post our sources here.
For example, mine is Espurr, a small, bipedal, feline Pokémon. Its fur is mussed and a pale grey color with the exception of its ears—which are cream-rimmed—and its paws, which have short cream socks. It has wide, annular lilac eyes with darker purple pupils. It has a small, triangular nose and tiny mouth. It has a small, fluffy, slightly curled tail. Its ears, quite large in proportion to its body, are folded- beneath them are two ring-shaped buff-colored organs. These organs emit Espurr's intense psychic powers, and said power would leak out were the ears not sheltering the organs. When its mouth is open, two pointed teeth can be seen on its upper jaw. Espurr are solitary in the wild; they act on their own and each values its independence. It is #677 in the Pokedex.
...Yes, I just ctrl-v'd that from Bulbapedia. I thought it'd be funny. :rrr:
Oh, and of course since Reverse Image Search exists, we should also post why we chose our avatar. For example, my usual avatar wound't fit, and I wanted to distance myself from my other accounts. Anonymity, you see. Anyway, I saw the Espurr one and thought it'd be funny.