freak

nouns

a person or animal that is markedly unusual or deformed
freak, lusus naturae, monster, monstrosity
someone who is so ardently devoted to something that it resembles an addiction
"a golf addict"; "a car nut"; "a bodybuilding freak"; "a news junkie"
addict, freak, junkie, junky, nut

verbs

lose one's nerve
"When he saw the accident, he freaked out"
freak, freak out, gross out