an infected rat  

I've been making mad loot for a low level Gnome Rogue. Killed these and "A Large Rat" from levels 2-4 exclusivly. Pretty common if you leave Ak'Anon, turn right, and go almost to the dragon skele. Lot's of rats and infected rats. Also look for "A Young Plague Rat", though tougher, you can make a lot of money from these as well. All three drop "A Plauge Rat Tail". Not sure what it's for, other than you can sell it for over 1 plat at the vendors.

Just ain't right man, my Dark Elf necro was well over 10 before I started seeing plat from a single kill.

ToXX ones are lvl 2 perhaps the lvl posted above is only for ToXX ones, the steamfont ones may be higher lvl....

It says they are all level2, but about 75% of the ones I have seen are from 4-5

Being easily the toughest MoB in the newbie area to the left of the Ak'Anon entrance, these are usually pretty rare at times when a decent amount of people are there. There is also a silly little quest with them; go to the guy behind the building with all the spellcasters' guilds and talk to him. Tell him his memory is slipping. He'll get angry and give you a foul-looking metal box to fill with 10 Infected Rat Livers. You don't get any item from the quest, but you do get a small amount of money and some xp. At the level at which you'd hunt these (3-4), I'd be in GFay hunting Orc Pawns or at LEAST camping the little Kobold camp near the newbie area in steamfont, but if you like beating up disgusting moldy rats (and probably being diseased a lot) you might as well do it.