Freak (Wally Kozielski)
WordNet
noun
(1) 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"
(2) A person or animal that is markedly unusual or deformed
verb
(3) Lose one's nerve
"When he saw the accident, he freaked out"