Dave’s Cool Toys Blog

For Christmas, my boys got a Grow Your Own Elf in their stockings. They are one of those little creatures you put in water and they soak it up and grow many times their size. So I found a large jug for them and my son, Josh, put his in. I think he expected it to grow in a few hours and was disappointed when the instructions said it would take 10 days.

But out of curiosity, we measured the "before" elf and he was 1.5 inches. The package said he would grow 600%, which would put him at 9 inches. (My son was not happy with me when I asked him to do the math on that one.)

So we waited, and watched, and he started growing in the jar on our kitchen counter. He was a lazy elf, lying on the bottom of the jar. We moved him when we needed the counter space, then put him back so he could continue to grow. Eventually, as he grew I realized the jar I used (a 1 gallon pickle jar) was a bit optimistic. And he never quite reached 9 inches. He stopped growing at about 6 inches on about day 4 and never really grew any more.

My wife thinks he looks like Butch Patrick. I’ll let you decide, he’s pictured here.

You can see from the picture on the right that my son took, that even though he didn’t reach his full potential, he sure grew quite a bit in 10 days.

Out of curiosity, I did some research to see why these grow creatures work. I discovered that they are made of a "superabsorber" similar to the material in diapers (also marketed as "Instant Snow"), combined with a polymer to keep their shape.
Specifically, they are "a plastic called a graft copolymer of hydrolyzed starch-polyacrylonitrile (commonly known as “Acrilan”, “Orlon” or “Creslan”)". Got that?

As I looked online, I discovered that these growing creatures make a great science experiment for school or home. Kids start with several identical grow creatures, and grow them under different circumstances, such as both tap and distilled water, or adding salt, sugar, or vinegar to the water and measure if they grow more or less. To see some interesting experiments done by Jack Spangler, a kindergartner, with grow creatures, check out his blog, here. It is excellent!

Now that I’ve composed this blog post, I’m wondering what would happen if I kept our little friend in water indefinitely. Will he continue to grow after, say 2 months? Or will he reach a limit? Well… we have one more, so check back in a few weeks!

One Response to “Grow Your Own Elf”