The exact location of the mob is between (L-11) and (M-11) on the first .map of Sea Serpent Grotto coming in from Yuhtunga Jungle. It's located in the doughnut shaped room at the southeast corner of the map.
We camped Fyuu for about 2 hrs killing every sahagin in the area, and he popped in the NW side of the room near the torch.
75PLD, 73PLD, and 73WHM took about a minute to kill it, not even sure if the 2-hour went off or not. Only had TH1, but got the Sardine and the Frog Trousers.
Edited, Wed Dec 22 18:28:36 2004