Object Oriented Programming - Change the Prototype to a New Object

Tell us what’s happening:
Describe your issue in detail here.

I don’t understand what this is supposed to do. I thought its supposed to add new properties to the objects created using the instance of Dog however when I console.log the beagle I made as an experiment in this course the outcome is simply the ‘name’ I gave the beagle.
Your code so far

function Dog(name) {
this.name = name;
}

let beagle = new Dog('rat')

Dog.prototype = {
// Only change code below this line
numLegs: 4,
eat: function() {
  console.log('nom nom nom')
},
describe: function() {
  console.log('big dog');
}
};

console.log(beagle)
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.134 Safari/537.36 Edg/103.0.1264.77

Challenge: Object Oriented Programming - Change the Prototype to a New Object

Link to the challenge:

you should be concatenating(+) the name of the dog with the string big dog