Tiny Apparition
Source: Pet Battle. It's more cute than spooky. Undead type. These share spawns with the neutral Tiny Apparition's that you can't battle. If there are no battle pets up, go around and kill all of the one you can't battle with and wait a few minutes.
Tiny Apparition is a wild battle pet found in the Helmouth Shallows of Tideskorn Harbor in Legion, where it shares spawns with non-combat versions of itself and other battle pets in the area.
Guide awaiting review
Head to Tideskorn Harbor
Travel to the Helmouth Shallows area of Tideskorn Harbor and search for the Tiny Apparition wild battle pet along the harbor area.
Kill Non-Combat Apparitions
If no battlable Tiny Apparitions are present, kill the neutral non-combat versions of the Tiny Apparition that cannot be battled, then wait a few minutes for battle pets to respawn.
Clear Kelp Scuttlers and Rapana Whelks
The area has a cap of around 3-4 pets total, so you must also clear Rapana Whelks and Kelp Scuttlers to free spawn slots. Engage them in battle and forfeit after the first pet dies — the entire group will then disappear. Note that Kelp Scuttlers cannot be killed outside of battle; you must start the fight to remove them.
Clear Level 1 Critters Too
Level 1 critters in the area also occupy spawn slots, so kill those as well to maximize the chance of a Tiny Apparition spawning.
Tips
Tiny Apparition is accompanied in battle by a Grizzly Squirrel and a Mud Jumper.
Tiny Apparition is reported to be identical to the Lost of Lordaeron in terms of abilities and breeds.