It is a common saying to parrots. It literally means what it says... do you want a cracker? This is often used in training a parrot's unique ability to "speak". It's the common command, much like "sit", "stay", "roll-over", etc are the norms for dog training. It was most likely popularised by the 1883 Robert Lewis Stevenson novel, Treasure Island as played out in the following scene (courtesy of pantoscripts.com): ------------------------------------------------------------------------ CUT-THROAT COLIN: Arrrhh! I ‘ad a pet parrot once! SKINT (With a parrot on his shoulder): Oh, really? CUT-THROAT COLIN: Arr! it used to lay square eggs! SKINT: Amazin’! Did it ever speak? CUT-THROAT COLIN: Oh, arrh, - what it usually said were - ‘Ouch!’ Parrot treats this remark with silent contempt. POOP DECK PETE: (To Captain Skint) Does your parrot bite? SKINT: Oh, no, my parrot definitely doesn’t bite! POOP DECK PETE: Oh, good, (to parrot) Who’s a pretty little Polly then? Polly want a cracker? (reaches out to tickle parrot patronisingly under the chin – the parrot gives him a fierce nip on the fingers) POOP DECK PETE: (Sucking damaged fingers and leaping about in pain) I thought you said your parrot didn’t bite! SKINT: It doesn’t – but that’s not my parrot -------------------------------------------------------------------------- While it's likely not the first use of the expression, Treasue Island has popularised many other "pirate" sayings; such as "yo ho ho and a bottle of rum" or "sixteen men on a dead man's chesT" (both of which it invented). From very early, it was common practice to name parrots (or more specifically, macaws) Polly. This is first attested by the 1611 play Volpone by Ben Johnson, in which he wrote of a parrot named Pol. And because, at the time, parrots were a new thing in the world to anyone but Incans and Mayans, as was the decision on proper names. And so begins the trend of naming parrots Pol, Poll, Polly, or Polly-O. Why these names? Ben Johnson was born in Westminster, but claims to be of a Border family (i.e. the border of England and Scotland). And it so happens that Pol is a Scottish variant of Paul, And because Ben is creddited with first naming a parrot Pol, we can thus link the naming of Parrots to "paul" as opposed to "polly" (a pet for of "molly", which is a variation of mary). -=UPDATE=- 1) Poll is British slang for a talkative person. When this came into use is not sure but it could explain why a parrot (who can "talk") was given the name Pol by a British author. 2) While not the origin, an old nursery rhyme went: Little Poll Parrot Sat in his garret Eating toast and tea; A little brown mouse Jumped into the house, And stole it all away. This could have been another source for it's wide spread as a parrot's name. 3) Parrots come from areas that were first settled by the Spanish. The Spanish word for chicken is pollo. These two may be linked some how- my guess being that Natives adopted the word (thinking it to be simaler to "bird") and used it for parrots- then the europeons re-adopted the term as a pet name? Hope this helps.

The script on pantoscripts.com, from which the extract below (= another answer) is taken, is a *parody* and *not* the original version, which can be found e.g. here: http://www.gutenberg.org/etext/120 The parrot in Treasure Island was called "Captain Flint". As far as I know, the phrase became popular through the cartoon "I wanna be a sailor" (1937), which you can watch here: http://www.youtube.com/watch?v=k1N7VcZovTE I can't guarantee that this was the first use of this particular phrase in the media, but it was the earliest usage I could find. The name "Polly" for a parrot is much older though (see the Oxford dictionary), but not in relation to a cracker.