I don't have a wiki or anything for iZombie-flavored zombies, but basically a romero is what happens when one starves to the point of losing sapience. They're pretty classic -- visibly rotting, nonverbal and snarling, a bit shambly until they catch the scent of a human then they're very strong and determined. All they want is to smash your head open for a snack. They only eat brains, so they go for the head and will leave the rest of the body alone.

They're pretty easy to kill compared to a fresh or sapient raging zombie, just aim for the head! But of note: they are super contagious! A scratch or bite will turn you, and the effect of that is pretty instant. If you were ill or injured that just doesn't matter anymore, and you'll start craving brains yourself. Within a few hours you'll go super pale and your hair will start turning white, and soon enough the hunger is impossible to ignore.

Hit me up if you get scratched? Drake can give you the team z talk.