This macro uses the 255 char max to target the rares in northrend. I tried this on test and got lucky and got 7 mobs on first run of Northrend. This macro was found on wowhead.

Quote:

/tar Ao /tar Dirke /tar Grie /tar High Thane Jo /tar Iceh /tar King /tar Old C /tar Putr /tar Seet /tar Terr /tar Vigd /tar Crazed I /tar Fum /tar Groc /tar Hildana /tar Loqu /tar Pero /tar Syr /tar Tuke /tar Vyr /tar Zul'drak Sen /tar Scarlet Highlord Da

There are a few false positives with this macro but once you get 1 or 2 of the mobs you can edit the macro. I would add in the time lost proto once you have a mob or 2 down. For that just "/tar time lost " should work fine for the line you will need to add
BOREAN TUNDRA
Icehorn
Level 71 Beast

Old Crystalbark
Level 72 Elemental

Fumblub Gearwind
Level 70 Humanoid

DRAGONBLIGHT
Crazed Indu'le Survivor
Level 73 Humanoid

Scarlet Highlord Daion
Level 73 Humanoid

Tukemuth
Level 73 Beast

GRIZZLY HILLS
Seething Hate
Level 73 Unknown/Uncharacterized (Fleshbeast)

Grocklar
Level 74 Giant

Syreian the Bonecarver
Level 73 Humanoid

HOWLING FJORD
King Ping
Level 71 Beast

Vigdis The War Maiden
Level 71 Humanoid

Perobas the Bloodthirster
Level 71 Humanoid

ICECROWN
High Thane Jorfus
Level 80 Humanoid(?)

Hildana Deathstealer
Level 80 Humanoid

Putridus the Ancient
Level 80 Undead

SHOLAZAR
Aotonap
Level 75 Beast

King Krush
Level 75 Beast

Loque'nahak
Level 76 Beast

STORM PEAKS
Dirkee
Level 80 Mechanical

Vyragosa
Level 80 Dragonkin

ZUL'DRAK
Griegen
Level 75 Undead

Zul'drak Sentinel
Level 77 Elemental

Terror Spinner
Level 75 Beast