I've been making sock monkeys out of fuzzy socks recently too. I think I just got a pair of socks really similar to your purple ones to make a monkey out of. With the exception of being covered in sock fuzz, I love working with these socks. They hide all of my not-so-good stitches.
That's adorable! My almost 15 year old brother who usually doesn't care about my crafty stuff saw your frog and asked me if I though it would be hard to make. I guess I know what I can make him for the holidays now. I love it!