Bike, Mouse, Hamster, Snake

Over breakfast this morning Alyssa started singing "I've got a mouse and he hasn't got a house, I don't know why I call him Gerald. He's getting rather old but he's a good mouse". 
Now if you know your Pink Floyd, you'll know this is from 'Bike', the last track on Piper at the Gates of Dawn. Stunned, I wondered where she'd heard it. I've got the LP, but don't think I've ever played it within her earshot. Turns out her maths teacher told the class he had a hamster called Gerald. 
"I don't know why I call him Gerald..." he said, and then launched into the song. He got quite carried away, playing a YouTube version on the white-board and before too long the whole class was singing along. Altogether now... "I've got a bike, you can ride it if you like. It's got a basket, a bell that rings and things to make it look good. I'd give it to you if I could, but I borrowed it".
He's also got a large snake, whose name was not revealed. Apparently it eats hamsters. He may have been teasing, but Alyssa said he was serious. Sounds quite a character. Oh, and his name is Mr Mason.