This article contains lore created collaboratively by the Blaseball community. It is just one of many Rumors that we've found in the Interdimensional Rumor Mill. You can find more Rumors about Haunt Wednesday at their Rumor Registry.
Haunt Wednesday is a ghost. She was summoned by members of the Pandemonium Artists during a late-night ouija board session. She does not remember how she died, who she was when she was alive, or how long she has been dead. Thankfully, none of that information is necessary to play Blaseball. Haunt's name was given to them by their teammates.
Haunt is known as Half-Star Haunt to fans, in an echo of Lars Taylor's "Lone-Star Lars" nickname. She is, actually, a six-star pitcher, but only on Wednesdays, the day after the Coffee Cup. When asked why she does not simply play well every day of the week, Haunt responded with ominous static sounds.