Here's what I've got so far:
From the CC:
- Beetles (boring, dragon, death watch, giant oil, slicer)
- Hallucigenia (standard, acidic, cave)
- Cave fisher
- Cave locust
- Cave moray
- Giant slug
- Flail snail
- Stegocentipede
- Serplar
Unconverted:
- Addazahr (backbiters) (MCA 2)
- Assassin bug (1E FF)
- Beetles (rhinoceros, water) (1E MM)
- Giant Tiger Beetle (Basic Set)
- Giant Bloodworm (1E FF)
- Burbur (MCA3)
- Cave cricket (1E MM2)
- Giant clams (various sources)
- Ear seeker (1E MM1)
- Giant flies (horse, bluebottle) (1E MM2)
- Giant locust (Basic Set)
- Parasites (various)(Savage Coast)
- Ploppeds (Mystara Appendix)
- Ringworm (MC 11)
- Robber fly (Basic Set)
- Giant spiders (crab, tarantella, black widow) (Basic Set)
- Scum Creeper (1E MM2)
- Tick, Giant (1E MM)
- Tick, Heart (MCA1)
- Trosip (Savage Coast)
- Wezers (Dark Sun CS)
- Whiz-Bang Beetle (Dragon #29)
- Giant shroud spider (OD&D - unsure of exact source)
- White widow spider (OD&D - unsure of exact source)