It is well worth the few dollars to obtain both the Lemur and the Heron. The Lemur gathers things for you such as...Tech Points (lots!), limestone, worms, magic, metal and other things as well. The Heron just eats frogs! When you get the crate about a crab... keep the crab. It beomes your pet. It doesn't do anything that I know of but... So far all crates I have opened have been good.