I recommend looking for “open course ware” (e.g. here or here) rather than MOOCs. These are usually course materials from the classes taught in-person at a university, which means they have actual prerequisites, and usually aren’t subject to the MOOC-esque pressure to dumb everything down to the most accessible possible level. (The latter link above includes the version of Ng’s ML course taught at Stanford, back in the day.)
I recommend looking for “open course ware” (e.g. here or here) rather than MOOCs. These are usually course materials from the classes taught in-person at a university, which means they have actual prerequisites, and usually aren’t subject to the MOOC-esque pressure to dumb everything down to the most accessible possible level. (The latter link above includes the version of Ng’s ML course taught at Stanford, back in the day.)