<?php

spl_autoload_register(function(string $name) {
    var_dump($name);
    if ($name === "Dog") {
        class Dog {
            function execute() {
                echo "I'm a dog." . PHP_EOL;
            }
        }
    } else {
        $class = new class {
            function execute() {
                echo "I don't know who I am." . PHP_EOL;
            }
        };
        $className = get_class($class);
        class_alias($className, $name);
    }
});

$myClassName = "Dog";
(new $myClassName())->execute();

$myOtherClassName = "Cat";
(new $myOtherClassName())->execute();