This plane algebraic curve
was named by
Maria Agnesi in 1748 although it had been investigated earlier
An equation for the curve is given by y(x2 + a2) = a3, for a constant real number a.
Apparently the name of witch coming from the Italian versiera
arises because Agnesi confused two different Italian words. Disappointingly, the curve has no supernatural properties. But if it
worries you I suggest throwing it in some water and seeing if it
Historical info sourced from http://www-groups.dcs.st-andrews.ac.uk/~history