NanTheWiser the cacti reference is about me not being very good with plants in fact cacti are just about the only ones I can keep alive. Here's a better picture, I actually don't have any more info shovetheholly ( great name btw!) my friend threw it at me on her way to work, she got it from her ex who she wants nothing to do with. I quite like it, she wanted to bin it!
Well, this is E. pulcherrima (Poinsettia), and I think it has a similar look to it as yours - I'm assuming it is an indoor plant? If you pick a leaf off, does it bleed white milky sap? (If so, don't get it on your skin as it could irritate...)