Deepridger
Drops from Karokta. The fire at the center of the world burns within its carapace. Elemental type. I found this pet by using this macro which lists all the rarer pets in the zone.
Deepridger is a rare wild battle pet found in Zaralek Cavern during Dragonflight, and is a rare spawn version of the Slabwing pet.
Guide awaiting review
Head to Sulfur Wastes
Travel to the Sulfur Wastes area in Zaralek Cavern. Deepridger has confirmed spawn locations at 41.77, 65.62, at 40.2, 65.6, at 49.4, 54.4, at 49.8, 60, and at 50, 52.8.
Kill Slabwings to Force Spawn
Deepridger shares spawns with Slabwing battle pets and critters in the area. Kill every Slabwing battle pet and critter you find to force a Deepridger to respawn in their place — expect to spend around 30 minutes clearing the area before one appears.
Use a Targeting Macro
Deepridger can be difficult to spot since it may not appear on the minimap and its nameplate shows in yellow rather than the usual battle pet color. Use this macro to target it: /target deepridger /script SetRaidTarget("target", 8); — hover your mouse over any creature you find to confirm it is a battle pet before engaging.
Capture, Don't Kill It
Deepridger cannot appear as a secondary pet in battles and is not required for the Safari achievement, but it is a rare spawn and worth capturing regardless of quality. Reduce its HP carefully and use a Trap — pressing the wrong button and accidentally killing it means waiting for the entire respawn cycle to begin again.
Tips
Deepridger is a rare spawn and does not count as a secondary pet, so the only way to obtain it is to find and capture the primary rare spawn directly.