(also spelled Dandan)
In Arabic legend, the dendan is a monstrous fish--large enough to swallow an entire ship in a single gulp--who nonetheless dies if it hears a human voice. It makes an appearance in Book 9 of The Thousand and One Nights, in the tale of "Abdullah the Fisherman and Abdullah the Merman." The two Abdullahs meet when the fisherman catches the merman in his net. They somehow become business partners and eventually decide they should hang out for a while at the merman's home. Fat from the dendan is made into an ointment, which the fisherman uses to cover his body so he can breathe under water. As the two Abdullas are enjoying a feast together, a dendan comes swimming along. The fisherman shouts at it, and sure enough, it dies instantly. I'm sure that was a great relief to the merman, who had no such powers of...what exactly would that be called? Lethal monster voice?
The dendan/dandan also makes an appearance in the Magic: The Gathering card game, in the Arabian Nights expansion pack.