Read about power levelling with a Hunter pet.

Get your lowbie grouped with anyone other than your Hunter. It could be an idle friend in Strath, as long as your lowie is grouped.

Have your lowbie tag a mob wihin his level or 2.

hit your Hunter's macro, with Attack on Assist to OFF.
/follow Lowbie
/assist Lowbie
/petattack

When you pet kills the tagged mob, your lowbie gets FULL exp as if he soloed the mob.