What is the term for this example?

[pam parker]

What do you call a word used in a poem or story that gets "manipulated" to create another word? For instance, in The Odyssey a soul in Hades is called a "shade." By taking the "s" in Hades and putting it in front of the word it makes a new word "shade." The original author didn't mean to do this since Homer did not write in English. I think it's cool how Hades and shade are interrelated and I think there is an English term that describes such. Am I right? If so, what's the term used to describe said example?

[queenbu]

Are you referring to 'anagrams'?
anagram:a word, phrase, or sentence formed from another by rearranging its letters: “Angel” is an anagram of “glean.”

I don't really know what poetry has to do with it.