I like this one!  you can make up your own actions to it and it's really easy to sing along to

Robin in the rain,
Such a saucy fellow.
Robin in the rain,
Mind your socks of yellow.
Running in the garden on your nimble feet,
Digging for your dinner with your long strong beak.

Robin in the rain,
You don't mind the weather
Showers always make you gay.
Bet the worms are wishing you would stay at home,
Robin on a rainy day — don't get your feet wet,
Robin on a rainy day!

fill the blanks

The song "Yellow Submarine" from the Beatles is a good song. We played a game where students had to fill in the lyrics. It was pretty successful in our classroom. http://www.youtube.com/watch?v=nkhTA6MQ3BQ

I taught my 3rd graders "Can an Elephant Jump" as one of my final lessons. We reviewed actions first, then the animals in the song. Then practiced the lyrics and sand the song together.
After I played hotseat with them (game ppt attached) I also printed out the lyrics for myself to follow along but you could easily put it on the screen for the kids to follow along that way too if the video goes too fast for them.

They had a lot of fun singing the song and doing actions with it (VERY important) even if they couldn't get every word of the song 

English lyrics and Korean Lyrics - with a Part 2 at the end of the song where students can use a worksheet to write the missing past tense words from the song

https://www.youtube.com/watch?v=_bA-kLCQiZQ