This is a link to one of my preschoolers' all-time favorite songs: "Octopus", by the talented Charlotte Diamond. We know it as "Slippery Fish", and this flannelboard story-song can be used as a springboard for teaching manners (you'll see), sequencing, and comparative sizes.
Slippery Fish Song
http://www.lair2000.net/Mermaid_Lyrics6/lyrics/Octopus.html