This example demonstrates object-oriented JavaScript patterns for modeling a zoo’s animal inventory, using a custom `Animal` constructor and a `Zoo` object literal to organize data. The code filters animals by leg count through the `Array.prototype.filter` method, separating bipeds from quadrupeds, and includes an `identify` prototype method that returns a descriptive string. The driver code runs assertions to validate the logic, while the Zoo’s `init` method initializes the animal list. No external visualization libraries are used; the focus is on plain JavaScript structure and functional testing.