Like so many of us, the best teaching ideas I have are "borrowed" from other teachers.  This one is no different and can be found in "An American Methodology" by Ann Eisen and Lamar Robertson.  I have actually not seen Ann or Lamar present this activity the way that I have used it.  Below I have shared a way that I saw Ann Eisen use it.

Sneaky Snake can work many ways and the stories you can use with it are infinite but the basic premise behind Sneaky is that he is a memory game.  In this version of Sneaky Snake, he was crawling along one day singing a familiar song ("Who's That Tapping at the Window?").  Now, Sneaky loves music and he loves to sing his songs a variety of ways.  Some days he sings the text of the song, other days he sings the solfa of a song but today he has decided he wants to sing the rhythm of the song.  The students would then sing the rhythm to "Who's That Tapping on the Window?"

But, as Sneaky was crawling along, singing his song, he came into some tall grass.  While part of Sneaky is now hidden in the grass, he's still singing the entire song, from beginning to end.  The students help Sneaky sing his song by singing the rhythm of the song again, including the part of the song that is now hidden by grass.

Again, Sneaky keeps crawling through the grass, singing his song.  ** You'll note that he crawls through the grass in 4-beat increments.

Of course, there are many variations to Sneaky.  When I took level III Kodály with Ann Eisen at CSU she used a story of Sneaky coming home dirty from playing in the mud and he had to take a bath.  As he washed off the dirt, the rhythms came off as well.  This variation allowed for the teacher to erase measures in a non-sequential order which provides a different challenge for the students.

One more thing: I learned after I created many copies of Sneaky was that if I made one or two Sneakys and laminated them I could then write the rhythms or solfa to songs with a Vis-a-Vis marker.  It saved a lot of time and the manipulative is then adaptable for a wider variety of song use.