Can a mass (planet or star) be so great that its own gravational pull prevents light from escaping it, thus would appear black or not appear at all?

Yes, That is what a black hole is or a dark star, a dark star is a star that could only live for a million years or so, its mass is equaled out perfectly. But of cource, none have been ob severed. Black holes have been seen and mapped by their effects on near by object like stars and nebulae.

normally black holes are the result of a supernova, collapsing onto it's self. i think lol.

A black hole is the remains of a star (usually one much bigger than ours) that has run out of fuel and has collapsed in on itself to a single point where space and time have become pretty meaningless.