int x = 20; // X-coordinate
int u = 14; // Units
float a = -0.12; // Angle

void setup() {
  size(100, 100);
  stroke(0, 153);
  smooth();
  noLoop();
}

void draw() {
  background(204);
  tail(x, u, a);
}

void tail(int xpos, int units, float angle) {
  pushMatrix();
  translate(xpos, 0);
  for (int i = units; i > 0; i--) { // Count in reverse
    strokeWeight(i);
    line(0, 0, 0, 8);
    translate(0, 8);
    rotate(angle);
  }
  popMatrix();
}