This visualization presents an interactive hierarchical tree of the animal kingdom, showing the classification from "Animals" down through vertebrates and invertebrates to specific groups like Mammals, Birds, Fish, and Amphibians. Built with D3.js v3, it renders nodes as colored rectangles connected by animated SVG links, with each node color-coded by its hierarchical level (type1 through type4). The layout uses `d3.layout.tree` with zoom and drag behaviors, and includes tooltips and click interactions to expand or collapse subtrees. Data comes from a JSON file structured with nested children arrays.