Hello Dugi & friends,
I’ve leveled up a 2x level 60 toons! And I’ve found & faced several errors or outdated steps in the Horde guide(s).
This thread will be filled up the issues I will face. Atm I’m leveling a horde toon again: Undead mage, so I will update this thread as much as I can, so Dugi can fix it 
29-12-2019: Progression – From Silverpine Forest (12-20) up to The Barrens (25-25)
The Barrens (25-25) – Step 10
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Same as The Barrens (22-23) – Step 10: Owatanka is still in the target macro + in the modelviewer and don’t target the “Silithid Harvester”. Link to Silithid Harvester: https://classic.wowhead.com/npc=3253/silithid-harvester
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I’ve also checked the whole place at the opposite direction / other Silithid area!
Suggestion: This mob is very & extremely rare
On my first toon I’ve searching this mob for like 3 days! Wasting of my leveling progression and time. Also on my 2nd toon I’ve searched it for 3-4 days! Now I can’t find it either on this 3rd toon! And I quit looking it from now, because it interfere my leveling progression time.
So maybe you can mentioned into the guide like: if you don’t find it, then it’s save to skip + skip step 36 because that step ask you to turn in the quest: “The Harvester”.
I even used the addon “unitscan” to track down (re)spawn of this mob. NO LUCK! Maybe the mob will be available on a later phase/patch
I know it’s available in retail.
For people who find & completed it: You’re very Lucky! 😮