Manny Calavera, a travel agent at the Department of Death.
Explore the Department of Death and try to participate in the poisoning event.
Unlike normal walkthroughs, in Nice Game Hints you can select just the puzzle you want hints for. Here are listed the puzzles for "El Marrow" in Grim Fandango. The guide you choose only contains information about that puzzle, reducing possible spoilers for other puzzles.