Grow Rudolph the Red Nosed Reindeer - Watch it Grow in Water Grow A Rudolph the Red Nosed Reindeer Toy Put in water and it will grow in size and it can be used over and over Size before you grow it is 1 1/2" high will start to grow within 2 hours and reach full size in 72 hours After removed from water and starts drying it will return to near original size