What word or phrase does your mother always say?
1640s, alteration of pompone, pumpion "melon, pumpkin" (1540s), from Middle French pompon, from Latin peponem (nominative pepo) "melon," from Greek pepon "melon," probably originally "cooked (by the sun)," hence "ripe;" from peptein "to cook" (see cook (n.)). Pumpkin-pie is recorded from 1650s. Pumpkin-head, American English colloquial for "person with hair cut short all around" is recorded from 1781. Vulgar American English alternative spelling punkin attested by 1806.
America's a dandy place:
The people are all brothers:
And when one's got a punkin pye,
He shares it with the others.
[from "A Song for the Fourth of July, 1806," in "The Port Folio," Philadelphia, Aug. 30, 1806]
A humourous term for the token - the object (notional or real) that gives its possessor (the "pumpking" or the "pumpkineer") exclusive access to something, e.g. applying patches to a master copy of source (for which the pumpkin is called a "patch pumpkin").
David Croy once told me once that at a previous job, there was one tape drive and multiple systems that used it for backups. But instead of some high-tech exclusion software, they used a low-tech method to prevent multiple simultaneous backups: a stuffed pumpkin. No one was allowed to make backups unless they had the "backup pumpkin".