Hockey pregame song

Tim Marino is a 20 year old engineering student at USC. He was born in Calgary, Alberta and had lived there his entire life. Tim grew up a victim of Canadian stereotypes, playing hockey and eating maple syrup. Because he played hockey, I asked Tim if him or his team had any rituals they would do before games. Tim said before every game they would sing the same song, and it goes as follows:

“There was a dirty bird (repeat), that had a dirty bill (repeat), that sat upon (repeat), my window sill (repeat), so I lured him in (repeat), with a piece of bread (repeat), SO I COULD SMASH (repeat), HIS FUCKING HEAD (repeat)”

Tim said they would sing this repeat after me song before every game as it would get him excited and get his blood boiling. Because it was an aggressive song, and because his entire team would get very into it, he said it would help them have more energy when they entered the game. I personally think the lyrics don’t matter as much as the team environment, with everyone chanting one thing in unison and yelling it as loud as they can. I just wonder why they chose these lyrics to sing.