Help, i have black spot on my big toe, what could it be?

Could be a few thing: A black spot can be anything from a freckle, to a mole, to melanoma. Most likely it is a freckle or a mole but it is important to get it checked by a dermatologist. If it looks like the picture it is probably a mole, but make sure you get it checked. Almost all types of dangerous skin conditions can be cured with early detection and treatment.