Baa'l
Source: Pet Battle. Not much is known about this otherworldly minion. Magic type. BFA Secret treasure hunt / paper chase: OVERVIEW: Extensive Overview for BFA Secrets here Secret Path 1: Extensive guide in my comment here Confirmed as first solved secret via dev twitter: 1/?
Baa'l is a secret demonic goat battle pet obtained by finding hidden pebbles in caves throughout Kul Tiras and Zandalar, then defeating it at 62, 22 in Frostfire Ridge.
Guide awaiting review
Complete Uuna's Quest Line
Before hunting the pebbles, complete the full Uuna quest line so she is upgraded and can properly weaken Baa'l during the final battle.
Gather Helpful Travel Items
Pick up a 
Goblin Glider Kit to reach hard-to-access cave locations throughout Kul Tiras and Zandalar, and bring an invisibility option such as 
Skaggldrynk to bypass enemies near certain pebble spots.
Start Path in Zandalar
Begin the pebble hunt at 45.87, 3.78 in Zandalar, which marks the path start for collecting the hidden pebbles scattered in caves across Kul Tiras and Zandalar.
Find the Ship Pebble
Head to 54.54, 7.3 and drop down onto the back of the ship; look for a skull with five pebbles beneath it and interact with the second one from the left, counting counterclockwise.
Collect Northern Pebble
Travel to 55.37, 11.99 to collect the next hidden pebble in this area.
Locate the Fatigue Zone Pebble
The next pebble is near 55.56, 52.61 in Azeroth, with a fatigue-free zone located just south of that point — use water breathing or swimming aids to safely reach it.
Defeat Baa'l in Frostfire Ridge
Once all pebbles are collected, travel to 62, 22 in Frostfire Ridge where Baa'l will be visible; use your upgraded Uuna in the battle to weaken it and claim the pet.
Continue With Waist of Time
After capturing Baa'l, the secret continues — obtaining Baa'l and 
Baa'l's Darksign leads into the next step of the chain, the 
Waist of Time.
Tips
A video guide covering the full pebble route is available — see the video guide for a visual walkthrough of each cave location.
