My dalmation molly(Oreo) terrorized my fish so bad that I gave him to a friend with bigger fish and more mollies. I had hoped he would leave her fish alone, I was wrong. About 3 days after I gave him up he bullied the wrong fish, he got headbutted into the glass and died later that day. Oreo was just flat mean, I have another small orange molly who is as sweet as can be. I wish I knew what made him mean but, I won't be getting any more. I know this doesn't give you any answers but I thought you would like to know it's not just your dalmation.
BTW, watch your other fish closely, Oreo ate the fins of a few of my fish. One of them even has septicemia because of it.
My dalmation mollie seems to be chasing or bullying my other fish ! my tank is new and still cycling and we did have two females for him ( as he is male ) but they both died the night we got them home so he's on his own . I have a sunburst platy and three diamond guppies , all are well and seem to be thriving but i am worried that the mollie is ' lonely ' any ideas ? 
