It's Easter Monday (or Pasquetta), so let's have a contest. In traditional term logic, a syllogism whose conclusion distributes the minor term but whose minor premise does not is guilty of the fallacy of the illicit minor, or the Father O'Malley Fallacy. A student of mine today suggested another name, the Father McPheeley Fallacy.
Anyone have any other suggestions?
And in the tradition of making up gestures descriptive of the fallacies, the one for this one is moon walking.