TheWoWDBI found the highest concentration of these snails on the sea floor just below the quest giver's cave, to the east, and slightly north. However, they can be found sticking to all sorts of terrain, hiding in the coral, and you're likely to see a handful while doing other quests in the area.
This macro should speed things along;
/targetexact Coilshell Sifter
/script SetRaidTarget("target", 8);
Quest
Don't be Shellfish
A World of Warcraft quest in Shimmering Expanse. Facts and objectives from the current retail game data.
The highest voted Wowhead comments for this page. They are community notes, not TheWoWDB comments.
Why wouldn't the shrimp share his treasure?
Because he was a little shellfish.
These Coilshell Shifters can be picked up on your mount, Vashj'ir Seahorse, which can make it much faster to do this easy quest.
Quest facts
LevelLevel 30-35
Quest ID25219
The client quest POI data records no map location for this quest, so no map is shown.
Check whether you have already completed this quest
in-game: /run print(C_QuestLog.IsQuestFlaggedCompleted(25219))
Description
I'm researching snails. Yes. Snails. When you're done laughing, maybe you can help. I'm sure you noticed the gigantic shellfish across the ridge... well, I'm pretty sure there's something inside it. It has several points that can only be mouths or entrances of some kind, and I've seen those sifting snails squeezing in and out. I'm thinking that we might be able to use the snails to gain entrance ourselves. That's the theory anyway.
Community notes from Wowhead · 24 comments
Top 3 shown aboveThe comments below were written by Wowhead users. They are community notes, not TheWoWDB comments. See them in context on Wowhead.
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Reward details
Reputation: The Earthen Ring +250
This gathering of the most powerful shaman of Azeroth seeks to maintain the balance between the world's elemental forces. Their main focus during the cataclysm has been to repair and stabilize the damage caused by Deathwing's arrival.
Reputation group: Cataclysm.
Other quests in Shimmering Expanse that reward The Earthen Ring reputation: Backed Into a Corner (+350), A Distracting Scent (+250), Totem Modification (+250), Undersea Inflation (+250), Slippery Threat (+250), Rundown (+250).
Item facts are the current retail client’s (ItemSparse); the specialisations for a pick-one item are the ones the Blizzard quest API lists; faction and currency text is the client’s own. Lowest listed price = the US commodity auction house now.