There are 2 monster(s) found that have the ability to use Back Stab:

Monster Mob
Lv.
HP Size / Race / Element Flee 95% /
Hit 100%
Skill
Lv.
Skill
Analysis
Gertie (Re-Stats) 141 266926 Medium / Demon / Poison 4 343 / 248 10 Go
Stalker Gertie (Re-Stats) 160 4057279 Medium / Demon / Poison 4 460 / 361 10 Go