The text is a play on the phrase 'Happiness is a warm puppy,' which is a famous quote by Charles M. Schulz, meant to evoke feelings of comfort and love. However, when attributed to an anaconda, a snake that might eat a warm-blooded animal, it takes on a darkly humorous second meaning, implying the anaconda's 'happiness' comes from eating the puppy.
" Happiness is a warm puppy , " said the anaconda .