Development is very loosely organised around the release managers of the stable and the development tracks; these are the two ``pumpkings''.
Perl development can also be divided up into several smaller sub-systems: the regular expression engine, the configuration process, the documentation, and so on. Responsibility for each of these areas is known as a ``pumpkin'', and hence those who semi-officially take responsibility for are called ``pumpkings''.
At the time of writing, the Pumpking for 5.6.x is Gurusamy Sarathy, and the Pumpking for 5.7.x is Jarkko Hietaniemi.
You're probably wondering why the silly names. It stems from the days before Perl was kept under version control, and people had to manually `check out' a chunk of the Perl source to avoid conflicts by announcing their intentions to the mailing list; while they were discussing what this should be called, one of Chip Salzenburg's co-workers told him about a system they had used for preventing two people using a tape drive at once: there was a stuffed pumpkin in the office, and nobody could use the drive unless they had the pumpkin.