The interaction of the Piranha Plant still runs even when one has been tongued which can hurt Mario if the plant points towards Mario. Fix this and the sprite can be accepted.
However, it also would be nice if you fix other issue with the interaction: The interaction routine also doesn't take care for Yoshi where it is possible to hurt Mario and not get thrown off Yoshi if you touch one from the bottom. Said routine also doesn't take care of sliding which also should be checked too.
Another issue which should be fixed in the next update is the lack of description of the extra bytes. I didn't know that increasing the extra byte value rotates the Pirana Plant counter-clockwise and such information is really important and should be put in the ASM file (preferable here) or included in a text file.