^ I've wondered the same thing before regarding 'Elephant' and also 'Animals'...
IMO, Elephant in The Professor is a sex reference = Male sex
But in Elephant, I think it refers to the drawing in the Cannonball single that Lisa did herself.
I had this theory that in The Professor, elephant = male sex and animal = female sex. That leads me to 'The animals were gone', not sure if he's talking about pets
or if he's saying that all the women in his life are gone
You don't need a lot of imagination to figure out what xtube is