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".