what does the "e" stand for in " wild E coyote " from bugs bunny?

The Coyote's name of Wile E. is obviously a play on the word "wily." The "E" was said to stand for Ethelbert in one issue of a Looney Tunes comic book; but only one issue, where its writer hadn't intended to create canon.

Actually it's Wile E. Coyote.

I don't know the answer to your question, but my guess is that it's a play on the word "Wily" as in crafty, mischievous, etc.

It's "Wile E. Coyote" so that the name sounds like 'wily" coyote or a coyote that is artful, sly, designing, intriguing, tricky, foxy, deceitful, treacherous.

It doesn't stand for anything the E is just emphasised. It is his descriptive name like Wily meaning artful and crafty like a fox is.