What to do if i removed my wisdom teeth, but what is that blackish stuff where the tooth was removed?

Blood clot: As no reference was made as to when your tooth was removed, the dark area could be several things. If during the first week after the extraction, the dark appearing area in the extraction site most likely represents the blood clot that forms following the removal of your tooth. If the extraction was performed several weeks prior, the dark area could be trapped food.