Most hated newbie mob?
 

I'll start.

Iksar Marauders
Krag Chicks
Mummies
Holly Windstalker

Ghouls.

How many deaths from getting ghoul rooted when you want to run?

Festering Hags

Nukes from Unrest trains slay many.

I remember having a hell of a time with the Orc Runner in Butcherblock back in live when I was a totally green noob and not so good at BB Frogger.

Guard Nash -
almost had that wolf dead. asshole.

Cazel

Vengeful lyricist and soloist are your worst nightmare as a barbarian newb.

Guard Cheslin.
Fippy if he agrod you on his kamikaze.
Decaying skeleton if you have no melee skills and have to burn mana.
Lyricists..

Mooto.

Head and shoulders and waist above all the rest. Pox of the Thicket.

decaying skeleton with a weapon on classic

can 1 shot level 1's if they holding rusty 2hander

Priest of Discord, he has caused more suffering for newbies than any creature in Norrath.