πετρούμενος ἀνεῖρπε

From LSJ

Γελᾷ δ' ὁ μωρός, κἄν τι μὴ γέλοιον ᾖ → The fool laughs even when there's nothing to laugh at

Menander

English > Greek (Woodhouse Quotes Reversed)

he crept up beneath a shower of stones