A name used to describe a hideously ugly guy or girl (more oftenly girl). A creatch-it is beyond a creature, which is a name for an average ugly person. Unlike a creature, a creatch-it can often be mistaken for something unhuman, hence creatch-"IT".
Person 1: "Damn that bitch is ugly"
Person 2: "Yeah bro... certified creatch-it"
Person 1: "Yo that new girl's in my class"
Person 2: "Is she hot?"
Person 1: "Nah dude, she's a total creatch-it"