This is Cyril's special lullaby that he sings to Cedric every night, to the point that Cedric can't get to sleep without it. It appears in the Season 1 episode "The Runaways!"
Note that this song is sung in-universe and is not used for The Raccoons' typical montage/music video sequences.
A dollar for your thoughts, my son
See money while you sleep
Watch those dollars jump the fence
Instead of silly sheep
And as each dollar earns its wings
Snatch it from the air
Do this a million times, my son
And you'll be a millionaire