How to change the prototype of "animal" and add method "sayName" to print statement

I've been doing a lot of HTML and CSS and now I'm doing a JS tutorial. I ran into this problem though. I don't know how to access the prototype.

Instructions:

Create a class named Animal with two properties, name and numLegs. The Animal constructor should have two arguments whose values are assigned to name and numLegs.

Next, change the prototype of Animal and add a method sayName that prints to the console "Hi my name is [name]", where [name] is the value of name.

Click "Stuck? Get a hint!" for examples of how to create a class and how to add a method to an object's prototype.

Finally, we have provided the last two lines to test your constructor and sayName method. Don't change these!

Here is my code:

// create your Animal class here
function Animal(name, numLegs)={
    this.name=name;
    this.numLegs=numLegs;

    this.sayName=function(){
        console.log("Hi, my name is "+this.name);
    }
}


// create the sayName method for Animal

// provided code to test above constructor and method
var penguin = new Animal("Captain Cook", 2);
penguin.sayName();

I get a syntax error. What gives?