It's the same size as a large red bird and when it hits a pig it eats it instantly (depending on pig type) and grows in size depending on what pig it is and when it grows it allows it to eat larger pigs if it hits a pig which is large and its only just able to eat it it will instead deal large damage untill eather the bird moves away or untill it eats it and grows and the larger it is the bigger the points you gain for destroying things with that bird so if something is worth 100 points and it grows it will be worth 125 points untill it grows again and the bonus will increase. It's quite rare.