$killTheCat = function($lives = 9) use (&$killTheCat) {
    $lives--;
    echo 'I KILLED THE CAT, ';
    if ($lives > 0) {
        echo 'BUT IT IS STILL ALIVE!'.PHP_EOL;
        $killTheCat($lives);
    } elseif ($lives <= 0) {
        echo 'AND IT IS DEAD.'.PHP_EOL;
    }
};

$killTheCat();
/**
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, BUT IT IS STILL ALIVE!
 * I KILLED THE CAT, AND IT IS DEAD.
 */