53...
My first ever Snape fanart, dated 2004. Which is telling, because my other HP fanarts are dated from 2001, the year when I started reading HP. But my first reading of HP was a very canon one, and my fanarts reflected that: they are mostly of HRH, the Weasley family, McGonagall, Fluffy, the Mirror of Erised... I actually started noticing Snape only with the scene depicted above, as I found the previous present-a-character-in-a-ebil-way-while-he's-not-truly-ebil-for-three-times-in-a-row quite uninteresting.
And of course, the first fanart I do, I mistake the Dark Mark's arm. Le sigh.
Happy Severus birthday, everywhere.