if(GameMath.randomNumber(1) > 0.85) {
    this.turnToAngle(GameMath.randomAngle(), 0.5);
}

if(GameMath.randomNumber(1) > 0.5) {
    this.variables.speed = GameMath.randomNumberBetween(0, 7);
}

this.setForwardSpeed(this.variables.speed);
this.playAnimation('walk', true, this.variables.speed / 5);