"I'm tough, but I'm no cookie".  

This sentence came from the TV show "American Horror Story". And what does it mean?

After having read the Urban Dicationay's explanations of "no cookie", I'm more confused now. How am I supposed to understand this sentence? 

The explanations of "no cookie" from Urban Dicationay are below:

no cookie

1. A negative response by a person being solicited by another person for a late-night hook-up in codewords.

2. Means wrong answer, or an answer not worthy of praise. Especially in an open forum.

A reference to rewarding children with cookies or other treats for good deeds.

Which explanation is better for this sentence? Or neither?