“My favorite animal is dogs.” Is this correct? It seems

the subject is “my favorite animal,” singular, and
the verb is “is,” also singular, so they match.

is “My favorite animal is dog” wrong too?

It looks like only the following are correct:

1. My favorite animal is a dog.
2. My favorite animal is the dog.

I like to use animal in singular form, so is there any differences in these two sentences?

Thanks.