While talking to him, if you choose the wrong thing to say you have to start all over again, making him one of the most frustrating errand to do in the event if one does not know the secret. He sees into the future, and his statements are the responses he would make to the question/answer that the player makes. For example, he'll appear to randomly say "That's rude!", responding in advance to the correct chat option of "You're an idiot." Many players do not read the actual dialogue with other characters hinting at this ability of his, leading to the frustration of trying to find a seemingly random chat option.
His examine option "He is in high spirits" is a pun because it is a ghost, which are similar to spirits, as well as the fact that he is drunk, and spirits can also mean alcohol.
The name of his band, Adamantite Damsel, is a pun on Iron Maiden, a British heavy metal band. (Adamantite and Iron are both metals, and Damsel and Maiden are both ways of referring to a woman.)
When asked about the line "Every rose has its thorn" the Grim Reaper will tell you "It was a long time ago in a dimension far, far away. It certainly wasn't an excellent adventure". These lines are references to several different things. First, the movie Star Wars ("A long time ago...") and second, the movie Bill & Ted's Excellent Adventure ("certainly wasn't an excellent adventure"). The line "Every rose has its thorn" also implies a reference to Bill & Ted's Bogus Journey, in which the Grim Reaper utters "Every rose has its thorn" to St. Peter when prompted by Bill. Incidentally, the line "Every rose has its thorn" is also a reference to a song of the same name by the glam metal band Poison, which would be a correlation to the heavy metal theme implied in Zabeth Corvid's character.
Sometimes when asked if he is drunk he will respond "Zzzzzzzzzz eat the bat Zzzzzzzzzz." This is yet another reference to Ozzy Osbourne.
A corvid is a bird of the family Corvidae, which includes the ravens; so, in a sense, Zabeth could be considered the third raven in the house, along with Edgar and Allan.