Sentinel's Companion

The Sentinel's Companion summons a companion owl called "Sentinel's Companion".

Source
This pet is a reward from The Huntresses.

Pet Journal
The companion of a night elf sentinel, rarely given out as a gift.

Note
Originally, the Pet Journal listed this pet as a reward from a quest called Little Sister Lost, even though it is a reward from the previously mentioned quest.

This spirit owl looks like a smaller version of Ban'thalos.