Hogarl is a fire giant who can be fought in the tier 3 battle 'Catching Fire' in The Black Pits. During combat, a message occasionally appears saying that he takes a swig from an ornate keg, though the effects of this are unknown.
The screen will shake, and this seems to inflict Sleep.
Its pretty resilient to mind altering spells. But you can cast slow on it and kite it. Head to head fight becomes a problem when it knocks you out with its special abilities and it often does.