Robin has a somewhat macabre side to her, and often points out gross or morbid facts, usually to the disgust of Nami or Usopp.

Robin will usually be the first to speculate that a crewmate has met or will meet with a horrible fate, often going into grisly detail. In other instances, she will express enthusiasm for anything with a horror theme.
Examples include:
- When Robin first joins the crew, Usopp asks her what her specialty is, to which she replies, Killing.

- When Luffy, Zoro and Sanji were exploring a galleon that had fallen from Skypiea and were eaten by a giant sea turtle, Robin immediately states that they may have been eaten along with the ship.

- When Nami asks if Zoro was eaten by the sky shark, she says that the clouds would be turning red if he was.
- When Nami is forced to swing on a rope past the sky sharks, Robin says the height is about 50 meters and she would die if she fell.

- Zoro and Nami return to the Going Merry in Skypiea but they cannot find Chopper, who was guarding the ship. Robin remarks that he may have been “shredded to pieces”.

- When Chopper is taken by the Foxy Pirates during a Davy Back Fight, Nami asks if Foxy is a collector of rare pets. Robin says, “Hopefully not a collector of rare pelts”.
- When the crew decide on the name “Thousand Sunny” for their new ship, Robin says that she was going to suggest the “Being of Darkness”.
- On Thriller Bark, she voluntarily investigates Thriller Bark with Luffy and Franky. She told Nami that she “likes thrills”.
- As Nami screams while testing the Mini Merry II on Thriller Bark, Robin remarks that she may have been cursed by a ghost.
- When they are attacked by the Cerberus on Thriller Bark, Robin says that she finds it “cute”.
