I briefly had a sansevieria, which I picked up half-dead at Canadian Tire because I felt sorry for it. I thought that the leaves would be too tough and unappetizing for my cats to nibble, but I was wrong. There is some debate over how toxic sansevieria is, but according to Plants are the Strangest People's Houseplant Toxicity Series, Sansevieria trifasciata can kill a cat. I've composted mine.
I should mention that I dislike the common names "mother-in-law's tongue" and langue de belle-mère for this plant, since they are a dig at mothers-in-law (the sharp leaves of the plant are supposed to be like the sharp tongues of mothers-in-law). I have had two mothers-in-law and they both are lovely people whom I am grateful to have known.