Any follower of Yoko Ono who believes in everything she says no matter what just because she was John Lennon's wife. (People who wouldn't give a shit about her if she wasn't with John wouldn't count as Ono Leeches.
"Oooh, I just got this new Yoko album!!"
"If it weren't for John, she wouldn't even sing, let alone get a record deal."
"Don't say that! She's amazing!"
"You're such an Ono Leech"