In GFX01, you'll need to paste or draw a vine over the fish and resave it as an ExGFX page, then the SP2 for the level to that ExGFX page. Then, there's a fix patch here that will make the vine green and not red, if you haven't already downloaded.
If your new to hacking and you want the classic pirahana plant vine ExGFX then download Demo World and extract the ExGFX and look at what the GFX setting is for SP2 in level 105 go to the ExGFX folder get the ExGFX with that number put it in your ExGFX folder insert the ExGFX and set the SP2 to that ExGFX file.
-------------------- the hack that I was gonna make Super Luigi World is being delayed due to another project of mine. I plan to create an editable Demo World: The Legend Continues,
however I still need a ? block that puts growing vine in the item box, ? block that puts a flying key in the item box, and white muncher GFX. After I insert these things I will be able to complete my DW:TLC pipes and blocks patch and then start working on the editable DW:TLC. If you would like to help me complete this project then PM me.