WASHINGTON — The turtle wearing a hat backward, baggy jeans and purple sunglasses looks just like other cartoon characters that marketers use to make products like cereal and toys appealing to children.

But the reptile, known as T. Top, who says creating and breaking codes is really “kewl,” is pushing something far weightier: the benefits of the National Security Agency.

To enter the “How Can I Work for N.S.A.?” section of the site, children click on a picture of a bucktoothed rabbit, who says in his biography that he likes listening to hip-hop and rock. In his free time, the bunny says, he participates in cryptography competitions with other cartoon characters named Decipher Dog and CryptoCat.

“As a signals analyst, you will work with cutting edge technology to recover, understand and derive intelligence from a variety of foreign signals found around the world,” children are told in the future employment section. “You will also attempt to identify the purpose, content, and user of these signals to provide critical intelligence to our nation’s leaders.”

Civil libertarians, not surprisingly, said the website was propaganda. Experts on early childhood education and marketing to children said the tactics used by the N.S.A. were similar to the way McDonald’s puts toys in its Happy Meals.