16-20 do Scarecrows in WK fields (
https://wiki.project1999.com/West_Karana ) #10 on the map. They're Undead mobs so you can use your 30mana Ward Undead nuke, and your 10mana fear undead spell.
If you don't have much of a mana pool, then pull with an Engulfing Darkness, Send Pet, Spook the Dead (UD Fear), Heat Blood, 1 Ward Undead, Sit/Med, re-fear as needed.
If you do have a big mana pool, pull with Darkness, and snare kite it with Ward Undead while pet beats on it.
I did this on a Necro 16-20 and it went pretty fast. There's often high level Druids / Shamans in the zone camping Ogres also, so you can usually grab some free HP buffs and Sow as well.