I once had a teacher who always wore stillettos and really bright colours, like pinks and turquoise. Her hair was always spiked and in my time of knowing her, has been green, blue, hot pink or yellow in colour. Her classroom is full of little plastic toys and dollhouses etc. She's always laughing too, and when she's nervous she talks fast. It doesn't take much to make her jump either.
My bio teacher is this little man who talks really really quietly. He doodles when he's bored and out of nowhere, during the lesson he'll throw in some quirky little comment, which means you have to give him all of your attention or else you'll miss it.
My music teacher subconsiously breaks out into song. He does it during assessments. It makes me giggle.