This scatter plot visualizes the relationship between flipper length and body mass for three penguin species (Adelie, Chinstrap, and Gentoo), using color-coded circles to distinguish species. The code loads a CSV from a GitHub repository via `d3.csv`, converts the numeric columns, and renders an SVG chart with `d3.scaleLinear` for both axes, `d3.axisBottom`, `d3.axisLeft`, and a `d3.scaleOrdinal` with `d3.schemeSet1` for colors. A manual legend built with SVG rectangles and text labels appears in the top-right corner.