Raw manta ray

Raw Manta Ray is a members-only item on the OSRS Grand Exchange in the other category.

In-game examine text: "A rare catch."

It has a Grand Exchange buy limit of 15,000 every four hours, a high alchemy value of 120 gp, and item ID 389.

View on OSRS Wiki

Raw Manta Ray shows an active flip setup with a margin of +32 gp and 379,997 trades over the last 24 hours.

At the buy limit of 15,000 every four hours, max profit per cycle is about 480.0k gp — high margin with healthy liquidity.