From Works and Days, a Latin tongue-twister and scribal exercise:
mimi numinum nivium minimi munium nimium vini muniminum imminui vivi minimum volunt
Which is something like, "The very short mimes of the snow gods do not wish at all that the very great burden of distributing the wine of the walls will be lightened in their lifetime." The good blogger Orwhalyus adds that it is "virtually unreadable in Black Letter script." I can imagine.
In a similar vein, I've always liked this line from Ennius: O Tite tute Tati tibi tanta tyranne tulisti! (O you tyrant Titus Tatius, what dreadful things you have brought upon yourself!)