Bring a large pot of salted water to a boil, then add the spaghetti and cook until al dente according to package instructions.
While the pasta cooks, heat olive oil in a skillet over medium heat. Add the minced garlic and sauté until fragrant, about 30 seconds, until it releases a warm, savory aroma.
Add the ground sausage to the skillet, breaking it apart with a spoon. Cook until browned and cooked through, about 8 minutes, until crispy edges form.
Remove the cooked sausage from the skillet and slice it into finger-like shapes, making sure to keep the shapes somewhat irregular for a creepy effect.
Drain the spaghetti and return it to the warm pot. Pour in the tomato sauce and toss gently to coat the pasta evenly, allowing it to absorb some of the sauce.
Add the sausage fingers to the pasta, arranging them so they look like severed fingers protruding from the sauce. Let everything cook together for another 2 minutes for flavors to meld.
Season the dish with salt and black pepper to taste, then serve immediately in bowls, making sure the sausage fingers are visible as a gory finishing touch.