Purpose of this guide is to list all the unique spiders and where to find them for people interested in completing the spider section of the monster manual and acquiring a spider companion.
I will try to list each spider and where I found it.
3500 spiders killed and 60 spider types found appears to be all you need to unlock the Companion.
The Companion is a Forest Spiderling a brown version of the Spider included with Xpack preorders.
The fastest way to get spider kills is to do Arachnophobia in harbor. Its a level 1 quest and you get 31 spiders killed per completion, completion takes under a minute. Second fastest in Vale Of Twilight Rare spiders and the spiders near the rare about 40 kills a run but a little longer than arachnophobia and no guarantee of the rare. Chance for a chest though. I rotated between the 2 areas to keep from getting too bored.
List of Spiders
Rares listed in Red
1. Ancient Arachnid - Trial By Fire Gianthold
2. Ancient Arachnid Queen - Trial By Fire Gianthold requires Knock or Unlocker.
3. Anth'narac- Deal with Demon - Demonweb
4. Astral Harrower - Demonweb
5. Baby Glass Spider - Caverns of Korromar sewer
6. Black Widow - Tangleroot Assault on Splinterskull, Various other quests.
7. Blood-Drinker - Tangleroot Assault on Splinterskull Yarkuch's War-plans. Second spider tunnel at start.
8. Brown Spider - Redfang, Various other quests.
9. Brown Spider Prince - Caverns Of Korromar Sewer
10. Brown Spider Queen - Arachnophobia in Harbor
11. Brown Twilight Spider - Vale Of Twilight wilderness by Djinn rare
12. Calamity - Smugglers Warehouse rare
13. Caligin - Shadowcrypt Rare Phase Spider
14. Ciac- Rare Korthos Island Wilderness
15. Crimson Foot Drone - Vale Of Twilight wilderness
16. Crimson Foot Herald - Vale Of Twilight wilderness
17. Crimson Foot Scout - Vale Of Twilight wilderness
18. Crimson Foot Shepard - Vale Of Twilight wilderness
19. Crimson Foot Slayer - Vale Of Twilight wilderness
20. Crimson Foot Soldier - Vale Of Twilight wilderness
21. Crimson Foot Worker - Vale Of Twilight wilderness, Note Do Rare for all Crimson foots.
22. Darkfang Hunter - Lots of quests, Red Fens wilderness
23. Darkfang Spider - Lots of quests, Red Fens and Hiding in plain sight
24. Deathjump Spider - Beyond the rift quest in Underdark area
25. Deluge - Bugged currently Phase Spiders count as this. Real Deluge is in Ataraxia and doesn't count.
26. Demonic Swarmhold spider - Demonweb wilderness
27. Demonweb Terror - Demonweb Wilderness
28. Dusk - Shadowcrypt rare phase spider.
29. Ecru - Waterworks wilderness rare behind secret doors.
30. Fencreeper - Red Fens rare
31. Fiend-Blood Spider - Various quests. Got mine in Ritual Sacrifice.
32. Fiend Blood Spider Queen - Bugged Jukeree in Vale counts as this instead of the Subteraan rare.
33. Fiendish Spider- Various Quests
34. Flame Eater - Spinner of Shadows
35. Frostbite - Misery's Peak
36. Glass Spider - Caverns of Korromar Sewer, various other quests
37. Glass Spider Queen - Caverns of Korromar Sewer
38. Grudge - Swiped Signet
39. Harrower - Underdark near traders camp
40. Hellgut - Ataraxia rare
41. Household Vermin - Dr Rushmore behind secret door
42. Ice Spider - Korthos wilderness and Misery's peak
43. Kraak - Stopping the Sahuagin Korthos
44. Large Spider - Underdark
45. Mandible - Snitch
46. Miasma - Garrisons missing pack rare behind secret door
47. Misery - Waterworks part 1 rare
48. Mother of the Nest - Dr Rushmore behind secret door in sewer.
49. Rrh'gitl- Rare glass spider in Demonweb.
50. Ruin - Sunken Sewer rare requires int rune to be activated.
51. Scourge - Swiped Signet
52. Silkweave - Rare Tangleroot wilderness.
53. Small Brown Spider - Arachnophobia Harbor
54. Spawn Of Whisperdoom - Assault on Splitterskull part IV or The Spawn of Whisperdoom
55. Spider Soul - Demonweb
56. Spite - Waterworks Part 1 rare
57. Swarmhorde Spider - Underdark near trader's camp.
58. Tsirrik - Trial by Fury named spider
59. Twilight Darkfang - Vale Of Twilight wilderness by Djinn rare
60. Twilight Widow - Vale Of Twilight wilderness by Djinn rare
61. Vicious Deathjump Spider - Demonweb
62. Vitia - Three Barrel Cove Rare
63. Websnare Spider - Beyond the Rift underdark section. Demonweb too I think.
64. Whisperdoom - Spawn of Whisperdoom, Assault on Splinterskull part IV (yes it counts if you kill her there too)
65. Whisperdoom's Daughters - Spawn of Whisperdoom, Assault on Splinterskull part IV
66. Whitefang - Schemes of the Enemy named spider in vents
67. Woathe - Proof is in the Poison Rare black widow
68. Mother- of- Thousands - Beyond the Rift Rare
69. Gloam - Tomb of the Shadow Knight Necro II Phase Spider Named. ( Thanks Jay203)
70. Restless Spider - A Small Problem
71. Shev'aal - The Portal Opens Named Spider optional
72. Frost Spider - Aussitcaex's Valley in Reavers Refuge (Thanks to Forgeborn for numbers 72-81)
73. Akorsta - Impossible demands, Take Hidden door that leads to attic
74. Bloated flame eater - Spinner of Shadows heroic normal
75. Clearfang - Cult of the six The fane of the six
76. Dimmet - Tomb of the shadow king Necro II
77. Glass twilight spider - Vale of twilight
78. Hyaline matriarch - Tomb of the forbidden Necro III
79. Pyrachnid - Ring of fire challenge
80. The Twilight mother - framework rare
81. Wood spider - Tomb of the blighted
Redfang - Redfang the unruled Not counted toward score or as unique spider
Deluge - Ataraxia Lighthouse quest, Not counted as a unique named spider, instead all Phase Spiders count as Deluge
Venom - Redfang the unruled Not counted toward score or as unique spider
Jukree - Counted as Fiend SPider queen instead of unique spider
Fiend Spider Queen - Subteraan rare, Not counted instead Jukree took its spot.
- All Quori Spiders like those found in I dream of Jeets, VON 2, and Dreaming Dark do not count as spiders.
- Guardian Statues in Portal Opens are not considered unique spiders but count as the spider they share their model with instead.
There may be some location mistakes, I'm going by memory, please post any corrections you see. And if you know a definite location of a spider other than listed please list it. If you know of any spiders I missed let me know and will add them.