Tuk-Tuks
Tuk-tuks have now come to Marrakesh and can be found in the Jemaa el Fna. They have no particular advantage over taxis, and are likely to try to charge more.
Common in India, where they’re called auto-rickshaws, tuk-tuks (so named for the sound they make) are basically a scooter with a frame, a couple of wheels and some seats added. In India, they’re nippier in traffic than taxis, and in India they cost less than taxis, but in Marrakesh they have no meter, will probably want more than the cab fare, have no particular advantage over a cab, and are less stable and less robust.
But they do make a change.