This is one of those cards where on the face it looks sort of awful for the format, but when I started to think of it in terms of a control shell that could provide a near constant Toxic Deluge when there is looting involved it started to get a lot better. It still might just be powerfully bad.
Dredge seemed to be the only place where you could actually get the thing into play with Dread Return or something, but since there are ways to get high cost permanents into play, Grixis Control also seemed to be a likely candidate where you'd also be running Dack and potentially JVP.
Every turn it could potentially waste out Mentor and token creatures, including zombies in the dredge mirror. I could also see utter silliness happening with things like Wheel or Windfall. Not that this is necessarily what those decks want to be doing, but still at 5/4 it could be decent?
But is it good enough at all? My initial reaction is probably not, but there may be some techy folk who could do better than I can off the top of my head.