lol, I did the same thing. I was all, wtf is this thing? and how do I get rid of it. I don't know how, but it occurred to me the only change I made recently was the alarm, so I turned it off and the icon went away.
I don't know what moto is thinking with this thing. If you're not going to make an alarm clock icon look like a clock, at least make it alarming...like an explosion or something.