Yeah, it's that one that folks don't know the name of. :) Seriously, no, there isn't a plant with the official name of Mystery Plant. You see monikers like that tacked onto ordinary plants in those cheap Sunday supplements and low-end garden catalogs to entice naive gardeners. And sometimes people just attach a "name" like that to a plant cuz they don't know the real name, and then pass it along. Although many folks have an aversion to scientific names, this is why they exist. Common names are all over the map, and are often unhelpful in telling you what plant you've got. Get a little more info from the guy, anything he can remember about the plant such as plant habit (e.g. bushy and clumping? running like a groundcover? etc), height, leaf shape (e.g. strap-like? heart-shaped? etc) and arrangement (e.g. rosette? growing off the stems? etc) and flower shape (e.g. daisy-like, petunia-like, etc), bloom arrangement (e.g. in a flat-topped cluster? single bloom? in a spike? etc) and flower color. With that info we could take a good whack at getting an ID. Marty

Not a Pothos, some kind of Philodendron, which I thought when I saw the 1st pic. Soil looks so dark what kind did you use? I hope you put some Perlite in there. These are tough plants, you needn't treat them as if they're fragile. In another couple of months, you'll be able to cut it back more, & place the cuttings back in the mother pot to help it be more full.

Looks similar to Ceropegia woodii, start by searching that one.

I'm sorry, but w/out a pic that's near impossible. No mention of the plant's growth habit, type or structure of leaves. Simply too little specific detail. Sorry, but you're basically you're asking for mind reading.