What is figgy pudding?

We want some figgy pudding
So bring it right here!
Figgy or fig pudding is a generic term covering a number of medieval dishes served at Christmas. These could be sweet or savory and usually included figs, honey seasonal fruits and nuts.
Later, figs were often omitted while large measures of rum or other distilled alcohol became obligatory

We Wish You a Merry Christmas

Figgy pudding has entered popular culture via the carol. This originated in the west of England and was revived in the Edwardian period by composer, conductor and organist Arthur Warrell (1883-1939). 

We Wish You a Merry Christmas is from the wassailing tradition, where villagers visit the gentry demanding ale to celebrate the season.  This combines jollity with a  barely concealed menace hinted at in the words:
We won’t go until we get some
So bring it out here!
Doubtless Mr Warrell played down the drunken rudeness in his five part madrigal version for the University of Bistol. 

If your guests 'won't go until {they} get some' you could try a recipe here.