Butterfly animation FLASH : https://dl.dropboxusercontent.com/u/15259519/flash/butterfly/index.html

Butterfly.as

package   
{  
	import flash.display.MovieClip;
    import flash.display.Sprite;  
    import flash.display.Bitmap;  
    import flash.text.StyleSheet;  
    import flash.text.TextField;  
	import flash.geom.Transform;
    import flash.geom.Matrix;
	import flash.events.*; 
	
          
    public class Butterfly extends Sprite  
    {
		[Embed(source = './butterfly.png')] private var img:Class;
		private var mright:Matrix;
		private var mleft:Matrix;
		private var step:int;
		private var left:Bitmap;
		private var right:Bitmap;
		
        public function Butterfly(x0:int,y0:int)   
        {
            left = new img();
            right = new img();
			
			left.visible = false;
			right.visible = false;
			
            addChild(left);
            addChild(right);
			
			x = x0;
			y = y0;
			
			mleft = new Matrix(0.5,0,0,0.4,x,y);
			mright = new Matrix(-0.5,0,0,0.4,x+130,y);

			step = 0;
			addEventListener(Event.ENTER_FRAME, onFrame);
        }
		
		function onFrame(event:Event):void {
			if (step == 0) {
				mleft.b = 0;
				mleft.a = 0.5;
				mleft.tx = x;
				mleft.ty = y;
				mright.b = 0;
				mright.a = -0.5;
				mright.tx = x+130;
				mright.ty = y;
			} else if (step == 4) {
				mleft.b = 0.2;
				mleft.a = 0.4;
				mleft.tx = x+12;
				mleft.ty = y-40;
				mright.b = 0.2;
				mright.a = -0.4;
				mright.tx = x+118;
				mright.ty = y-40;
			} else if (step == 8) {
				mleft.b = 0.1;
				mleft.a = 0.3;
				mleft.tx = x+24;
				mleft.ty = y-20;
				mright.b = 0.1;
				mright.a = -0.3;
				mright.tx = x+104;
				mright.ty = y-20;
			}
			
			var tleft:Transform = new Transform(left);
			var tright:Transform = new Transform(right);
			tleft.matrix = mleft;
			tright.matrix = mright;
			left.visible = true;
			right.visible = true;
			
			step++;
			if (step == 12) step = 0;
		}
    }  
}  

Main.as

package   
{  
    import flash.display.Sprite;  
    import flash.text.StyleSheet;  
    import flash.text.TextField;  
	import flash.events.*; 
          
    public class Main extends Sprite {
		private var butterflies:Vector.<Butterfly> = new Vector.<Butterfly>(10);
		public function Main() {
			var i:int;
			for (i = 0; i < butterflies.length; i++) {
				butterflies[i] = new MovingButterfly(150, 100, 300, 200);
				this.addChild(butterflies[i]);
			}
		}
	}
}

MovingButterfly.as

package   
{  
    import flash.display.Sprite;  
    import flash.text.StyleSheet;  
    import flash.text.TextField;  
	import flash.events.*; 
          
    public class MovingButterfly extends Butterfly {
		
    private var x2:int;
    private var y2:int;
	private var w1:int;
	private var h1:int;
	private var spd:int = 30;
	private var counter:int;
 
    public function MovingButterfly(x0:int, y0:int, w0:int, h0:int) {
		super(x0,y0);
		x2 = x0;
		y2 = y0;
		w1 = w0;
		h1 = h0;
		counter = 0;
		this.addEventListener(Event.ENTER_FRAME, onFrame);
    }
	
	override function onFrame(event:Event):void {
		counter++;
		if (counter > 10) {
			var rnd = Math.floor(Math.random()*30);
			if (rnd == 0) {
				x2 = Math.random()*w1+30;
				y2 = Math.random()*h1+30;
				counter = 0;
			}
			x += (x2 - x) / spd;
			y += (y2 - y) / spd;
		}
		super.onFrame(event);
	}
	
	}
}