Monster creepy;
boolean doSave;

void setup(){
  size(800,400);
  smooth();
  creepy = new Monster( 200, 120, height-18, 4, 2 );
  frameRate(30);
}

void draw(){
  background(255);
  creepy.update(mouseX);
  creepy.draw();
  if( doSave ){
    saveFrame("stills/slider_####.png");
    doSave = false;
  }
}

void keyPressed(){
 if( key == 's' ) doSave = true; 
}