X ревел белугой - X was crying hysterically
X was crying (yelling, bawling) his head off
(in limited contexts) X was howling like a jackal (a hyena)).
(Львов:) Скоро благословение? (Косых:) Должно, скоро. Зюзюшку в чувство приводят. Белугой ревёт, приданого жалко (Чехов 4). (L.:) Will the benediction be soon?
(К.:) It should be soon. They're trying to bring Zyuzyushka around. She's howling like a jackal.. .upset about the dowry (4a).
Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.