I have Bantam welsummers, Bantam Olive eggers, MGB, LF Buff and Golden Laced polish x Tolbunt, d'anvers, Bantam wyndottes, Lavander Orps. and bunch of free range birds
Leaning towards Roo
My past experience with Cochin Bantams makes me remember they are slow developers.
A comb of that size at that age regardless of color is suspect.
Definitely a rooster. Also that's funny I have a 9 week old BSL pullet named Penguin, too!