I say either a pictus or this member of the sydontis family: http://malawicichlids.com/mw11003a.htm

They look very similar...check out the rear fins, as well as the barbs...the pictus has a set of very long barbs, whereas the sydontis has much shorter ones.

Either way, the spines on both pictus and sydontis are very sharp and could be deadly for your O should he choose to eat it.