It is unknown when and how he came to The Island nor why he chose to say.
His job in the colony was to wash the laundry with Friday Caliban and Professor Fletcher, washing everyone's robes in the saltwater falls and laying them on the rocks to dry in the sun. Robinson also rinsed seaweed with Sherman for meals.
While storm-scavenging the day that Violet, Klaus and Sunny Baudelaire wash ashore, Robinson finds a pair of overalls. Though Violet wishes to use them to keep her robe clean while inventing, Ishmael reminds him that the colony traditionally wears only white, so Robinson discards the overalls onto the sleigh to take to the arboretum. Violet later ends up assisting him with the laundry.
Robinson is likely among the crowd of islanders who go storm-scavenging the day that Count Olaf and Kit Snicket wash up ashore, with Kit on a raft of books. The colonists leave to go fetch Ishmael to decide what to do, leaving Olaf under the watch of Friday Caliban and the Baudelaires. He is presumably still with the crowd when they return, and Ishmael convinces them to abandon Olaf, Kit and the Baudelaires on the coastal shelf.
When the island has a mutiny over breakfast, Robinson is seen tugging his beard at Larsen. Ishmael shoots Olaf with a harpoon gun, which causes the Medusoid Mycelium to be released, poisoning the islanders. Ishmael suggests the islanders drink cordial to try and dilute the poison, and the fermented cordial drugs them into compliance. He convinces them that the Baudelaires are the root of the trouble, and then gathers them on the outrigger and has them sail off towards Lousy Lane for a cure, though they will not make it in time to save their lives.
It is unknown if he met his fate by being poisoned by the Medusoid Mycelium. It is noted that the Incredibly Deadly Viper followed the boat with an apple, and as the Baudelaires did not know this, it is possible some islanders survived to report this to Lemony Snicket. Friday knew the snake to be friendly, and thus may have taken the apple from it; however, it is unknown if she would have been able to convince Robinson or the drugged islanders to eat it.
- He is named after the titular character in Robinson Crusoe, a novel by Daniel Defoe.
- The novel is one of the most famous castaway stories, telling the tale of a man who spends twenty-eight years on a remote tropical island.
- The novel also features a character named Friday, possibly providing the name for Friday Caliban.
- While he makes no physical appearance in the Netflix Adaptation of The End, he could still potentially be one of the unnamed islanders.
- He has no spoken lines in the book.