'Doctor Who' fan favorite River Song is a frizzy haired archaeology professor (sometimes) with a confusing timey wimey past, present and future. Ms. Frizzle is a teacher with a magic transmogrifying school bus and a chameleon companion.

It's currently up for debate, but Ms. Frizzle may or may not be the continuing adventures of River Song after she left/leaves this plane of existence. Damn time travel shenanigans.

In the BBC television series, River Song is played by the wonderfully sassy Alex Kingston -- and she has a back story so complicated that to tell you about it would be to ruin the timeline of three whole seasons of the long-running show. Just trust us when we say it's awesome.

Ms. Frizzle is the delightfully quirky fictional teacher who taught her class all about science through the use of magic and child endangerment in the book series and later on the show 'The Magic School Bus.' Her students would later grow up to be the Planeteers, so she obviously did everything right. Bonus: No one ever died. Not even Arnold.