Ishmael is the island's facilitator. He was once a member of V.F.D., and has the tattoo of the organization on his ankle, although he attempts to hide this by concealing his feet with clay. He claims that Count Olaf once locked him in a giant bird cage and burnt down his house, although Olaf counter-claims that he did not set that particular fire. Ishmael once knew the Baudelaire parents; they were the island's facilitators when he arrived, but he forced them into exile and imposed his own views on the island colony.

In his role as facilitator, Ishmael is in charge of solving the islander's problems, as well as sorting out all the things that they find on the coastal shelf. He is very capable at persuading the islanders to get rid of items they've discovered, telling them, "I won't force you", but giving them little other choice. His decisions on whether or not to keep the items are usually illogical, but the islanders follow his suggestions due to peer pressure and mob psychology- rather in the same way that Olaf used it in The Vile Village. Moreover, the coconut cordial that Ishmael persuades everyone to drink also plays a role in this because it serves as an opiate, making them drowsy and have difficulty making decisions for themselves. The items that Ishmael pronounces as useless are taken to the arboretum on the other side of the island on a sledge drawn by island sheep. He does not allow the islanders to keep secrets, but has many of his own; such as being able to walk despite claiming not to be able to, and eating the forbidden apples from the arboretum's tree. He claims that his feet are injured, preventing him from walking, and covers his feet with island clay. He claims the clay has magical healing powers, but he is really using it to hide the V.F.D. tattoo on his ankle, and frequently sneaks around to visit the arboretum when nobody is with him. Count Olaf thus described him as having feet of clay, a reference to a Biblical quotation meaning that one has a hidden weakness.

In the middle of the book, he had Count Olaf sealed inside a large birdcage and pressured the islanders into abandoning the Baudelaires on the island's coastal shelf, even though he knew that the shelf would soon flood, drowning the orphans and Olaf. Later, he met the Baudelaires in the arboretum, telling them to give up their former lives and lead a safe life on the island. Not long after, upon discovering that the islanders are mutinying against him, he revealed that he was able to walk and used a harpoon gun to shoot Count Olaf, fatally wounding him but inadvertently releasing the deadly Medusoid Mycelium.

Finally, he put the islanders' lives at stake by taking them away from the island on an outrigger and depriving them of a cure for the Medusoid Mycelium, although he had eaten a sample of the cure himself, which meant that he was "immunised" against the poison of the Medusoid Mycelium. Although the Incredibly Deadly Viper attempted to deliver a cure to the remaining islanders, it is unknown whether it succeeded.

Ishmael's name is taken from Herman Melville's novel Moby-Dick; he often asks people to 'call me Ish', a parody of Moby-Dick's opening sentence, 'Call me Ishmael'. However, only Count Olaf refers to him by this nickname.