Pretty cool. I had made a similar one too though it's a little more ambitious:

y = arsinh x (inverse hyperbolic sine of x):



y = sgn(x)⋅|x|^{cos x} (sign of x times the absolute value of x to the power of cosine of x):



y = 2x^⅓+½⋅sin x (doubled cube root of x plus halved sine of x):



Looks a lot better when you see it animated.