I’ve seen some different frog designs, and here’s a pretty simple one that I like. It uses a green 260 balloon for the frog body, and a bit of yellow or white (you can use a leftover scrap) for the eyes.
See the video here. (The person in the video has also made many other videos which are available from the same site, and are worth a look.)
Comments on the video instructions: You will want to leave about a 4.5 inch tail when blowing up the green balloon. I quickly ran out of “balloon” and had to make sure not to make any bubbles too large. If you do find that you’ve run out of balloon, you can just make the two legs from a second green balloon and then attach them.
To make a simple snake: just make the head of the frog. When blowing up the balloon, leave a smaller tail (around 1.5 inches), as you won’t be making as many twists. After making the head, bend the rest of the balloon into a zig-zag shape. Push the air into the uninflated part of the balloon. I also attached an uninflated piece of leftover red balloon for the snake tongue.