Yes
It's about a 1% drop from the greater nature sprites that spawn from Ent Ancients when "buffed".
Generally, white bags are belived to drop at a rate of ~1% or less.
In order to attempt to receive a sludge sword drop from a monster on Adventure Quest a player must do the Sunday Sludge sword quest at Valencia. The Grumble monsters are what are needed to be slain for this drop.
Drop A.
around 50%
cursed bone sword
the drop bear
Console command, or even better yet, Pick up the sword and drop it in the Jarls quarters.
Obtained as a drop from Commander Zilyana in the Saradomin Encampment of the God Wars Dungeon.
I assume that you are talking about "black nights" They drop bones, various runes, seeds(members only), and various charms for summining(members only) They also drop equiptment: Iron sword, iron full helm, steel mace, black full helm, mithril arrows, black 2h sword, black sword.
Sludge sword is the reward for Valencia's quest "Sunday... Sludge Sword!". To complete the quest you must kill Grumble in the sewer (/join sewer) and get the drop "a rare unidentified sword."
Monsters in the god wars dungeon drop them. They're really hard to beat though.