This little jingle is usually used to teach kids about the sound of the letter S, but it fits with the reptile theme as well:

Seven silly salamanders sitting on a swing,

Swaying in the sun singing silly songs and things,

Seven silly salamanders suddenly stop,

And say, hey silly salamander let’s speed it up!

(Repeat the verse a little faster each time.)

Snake Dance (All Ages)
Put on some music and have kids dance like a snake, moving their arms and body in a slithery, snake-like motion while sticking out their tongue and wiggling it like a snake.