=== snake ===

sqrt(triangle_wave(x + sqrt(triangle_wave(x + 0.4 * sin(y*3)))))

=== swirl ===

gaussian_curve((x^2) mod (abs(sin(x + y)) + 0.001) + (y^2) mod (abs(sin(x - y)) + 0.001))

=== cables ===

r = sqrt(triangle_wave(0.9 * x + sqrt(triangle_wave(sin(x + 0.2 * triangle_wave(2 * y) + 0.6 * sin(0.5 * y))))))

=== pills ===

sqrt(abs(sin(x + cos(y + sin(x + cos(y)))) * sin(y + cos(x + sin(y + cos(x))))))

=== hourglass ===

logistic_curve(angle_rad(sin(x^2),sin(y^2),triangle_wave(y),triangle_wave(x)))

=== yin yang ===

r = sin(1.2 * y + 2.5 * sin(x) + 2 * cos(2.25 * y) * sin(x)); log(2 * sqrt(abs(r)) - r).

=== prime spiral ===

a = angle(0,0,x,y) / (2 * PI);
d = floor(dist(0,0,x,y) + a) - a;

d *= 2;
d *= d;

return floor(d) + 1000 * isPrime(d);
=== weird (randomly found) ===
return sqrt(sqrt(((x) % (y)) / ((rand()) + (y))));