“I shouldn’t have had seafood because now I’m feeling a little eel”

“I knew I shouldn’t have had the seafood because now I’m feeling a little eel” is a jocular one-liner that has been printed on many images. “You’ll have to excuse me, I’m feeling a little eel” was posted to the newsgroup rec.arts.tv.mst3k.misc on April 6, 1996.
 
“I ate some seafood and now I’m feeling a little eel” was posted on Twitter on September 1, 2013.
 
       
Google Groups: rec.arts.tv.mst3k.misc
They Don’t Know Who… (Fish Pun Cascade)
Doug Elrod
4/6/96
(...)
“You’ll have to excuse me, I’m feeling a little eel”
 
Google Groups: alt.humor.puns
My favourite tunafish joke
Raz Cactus
5/26/00
(...)
I got a really severe haddock from all this singing and am feeling a little eel.  Hopefully a sturgeon will be able to fix me.
 
Twitter
Seth Curry‏
@setha85
I ate some seafood and now I’m feeling a little eel.
2:15 PM - 1 Sep 2013
 
Twitter
Dylan‏
@DylanPockett
Just ate some seafood, now I’m feeling eel.
1:53 PM - 18 Sep 2013
 
Twitter
niall omg‏
@irishhampster
Replying to @harrystahp27
@louisismine27 I knew I shouldn’t have eaten that seafood…I’m feeling a little..eel
3:28 PM - 14 Jan 2014
 
Twitter
dads bad jokes‏
@jokes_dads
I knew i shouldn’t have ate that seafood. Because now i’m feeling a little… Eel
12:04 PM - 17 Jan 2014
     
Independent (UK)
June 15, 2014
Father’s Day 2014: The 20 Best Dad jokes (and how to tell them)
Stuart Henderson
(...)
14. I knew I shouldn’t have had the seafood. I’m feeling a little eel
   
28 February 2015, News Mail (Bundsberg, Queensland), “Last Laugh,” pg. 19:
I knew I shouldn’t have ate that seafood.
Because now I’m feeling a little eel.
   
Knowable
February 29, 2016
50 Ultimate Dad Jokes. Who Said Parenting Couldn’t Be Fun?
(...)
9. I knew I shouldn’t have eaten that seafood
because now I’m feeling a little eel.