USA 1920: ‘to have the brains of a goldfish’ (to have limited intelligence)—USA, 1958: ‘to have the memory of a goldfish’ (to be unable to retain information or memories for any significant length of time)
American English, 1874—used in particular of stupidity, as in ‘dumb as a bag of hammers’ and variants—the underlying notion is probably that anything is dumb that does all the hard work
the principle that, where an effective legal system is absent or does not apply, brute strength and self-interested ruthlessness are what determine success, ownership, etc.—USA, 1878—predates Kipling’s Jungle book
USA, 1977—petroleum, and any liquid derived from petroleum used in a vehicle powered by an internal-combustion engine—perhaps from popular association of ‘dinosaur’ with ‘fossil fuel’
UK, late 1980s—the adverb ‘o’clock’ is colloquially and humorously used with adjectives to denote an unreasonably, excessively or inconveniently early or late hour—as in ‘stupid o’clock’, ‘silly o’clock’, etc.
one’s feet as a means of travel, humorously represented as a form of public transport—from 1887 onwards in the southeastern states of Georgia and Alabama
USA, 1882—one’s boots or feet as a means of travel, humorously represented as a form of public transport—refers to boots with hobnails inserted into the soles
USA, early 1930s—adjectives—‘little-girl-lost’: resembling (that of) a small girl who has lost her way—‘little-boy-lost’: resembling (that of) a small boy who has lost his way