1609—to add to what is already great, also to add difficulty to difficulty—Pelion and Ossa are two mountains in Thessaly—in Greek mythology, two giants, Otus and Ephialtes, tried to pile Pelion and Ossa on Olympus in order to reach the gods and overthrow them
UK, 1849—transformation into a pumpkin; extravagant or absurdly uncritical glorification—coined after Hellenistic Greek ‘ἀποκολοκύντωσις’, the title of a travesty ascribed to Seneca, according to which the deceased Roman emperor Claudius, instead of being elevated to divine status, is changed into a pumpkin
UK, 1869—used to denounce arbitrariness—alludes to a demand by the Queen of Hearts during the trial of the Knave of Hearts in Alice’s Adventures in Wonderland (1865)
1696—perhaps from ‘latet anguis in herba’ (a snake hides in the grass) in Virgil’s Eclogues—cf. ‘a pad [= toad] in the straw’ and French ‘il y a de l’oignon’