Totem Companion( Eberron Campaign Setting, p. 61)
Instead of an animal companion, you have your totem magical beast as a companion.
Beast Totem (ECS) , ability to aquire a new animal companion, Minimum level requirement (see below), Wild Empathy class feature,
When choosing an animal companion, you may choose a magical beast of the same kind as your beast totem. Even though your companion is a magical beast, you can cast spells on it that normally target animals as though it were an animal. Apply the indicated adjustment to the character's level (in parentheses) to determine the companion's special powers (see Alternative Animal Companions, page 36 of the Players Handbook). Rangers who choose this feat use one-half their level to determine what companions they may attract.
7th Level or Higher (Level -6)
10th Level or Higher (Level -9)
13th Level or Higher (Level -12)
16th Level or Higher (Level -15)
The totem companion has all the normal abilities of a typical creature of it's kind, as well as the characteristics of an animal companion determined by your druid or ranger level.