Adobe Illustrator. Traced shapes off a photo of spider. Shapes tool, pen tool, pencil tool were all used to form all the parts. Duplicated some of the legs to save time. Lots of gradients to fade colors to give volume. Web was basic paths for the first few lines then duplicated with the rotation tool. Copy and pasted a bunch and added different gradients and opacity. Outer glow on the black widow and its web. Duplicated on top of itself for more glow. Radial gradient background black to light blue.