I noticed that some drops from monsters aren't listed on the wiki. Here, I'm making a list of missing drops. This is constantly being updated. Post any other missing drops you see and I'll update it. The monsters will be sorted in the order they're shown on the wiki, with spaces between monster types (for example Wolvers and Chromalisks) and --- between monster families.
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Ironclaw Thwacker: Spark Plug.
Tenderfoot Mender: Spark Plug.
Ironclaw Mender: Spark Plug.
Ironclaw Demo: Bronze Bolt.
Gremlin Knocker: Spark Plug, Fine Fabric.
Gremlin Choker: Spark Plug, Unstable Core, Waste Module, Nightshade, Toxic Core, Miracloth.
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Caustic Polyp: Driftwood, Nightshade.
Glop Drop: Driftwood.
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Spookat: Vile Seal, Dead Gold.
Slag Walker: Vile Seal.
You've stumbled upon a huge pile of problems. Most of the main material page and relevant pages need updating. I don't think a large chunk of this "huge pile of problems" has been fixed since Release 2013-07-30, when "2 star materials and higher now only drop from a specific monster family."
Page history shows a few efforts in a good direction.
Lots of work ahead.
Now, if only the in-game Item Finder would actually work properly...lol.