A beholder, minus nine eyestalks and the entire main body. Also very complicated to rate.
The reason for that is that at low levels (2-4) lurking stranglers are awesome. Flight, Tiny size, +8 dexterity, and the ability to fire off two save-or-loses per round makes for one considerable threat, for obvious reasons. The thing is: those two save-or-loses only work on foes with less than 5-6 HD, meaning they start getting consistently useless from level 4 on, and are basically worthless past level 5. Without its eye rays, I don't think I'd assign the lurking strangler anything more than -0 LA.
Initially, I assigned +1 here, but I must disagree now. The strangler's lack of speech, limbs, or body slots mean that it's struggling even at ECL 2. While I'm not entirely sure I agree with -0* (the asterisk referring to the eye rays), I'll follow the majority and assign just that.