This beautiful song is perfect for practicing using the subjunctive for expressing wishes/hopes.
Also, the creativity in the metaphors gives students plenty to interpret (I have them work in small groups) while expanding their vocabulary. At the end of this activity sheet, students can put that creativity to practice by writing another verse to the song.
I posted an earlier, much simpler version of this song activity back in 2012, but here is an improved activity sheet with the discussion questions on the actual handout.
Hablando de osos polares, aquí está una canción que se llama, «El oso polar» de la banda mexicana Hello Seahorse! Pero, ¿como se dice «seahorse» en español?El hipocampo o el caballito de mar.