If you probably have it in one of your plants is horrible is a rank 2 pest I had one on my snap dragon and helephant ears you can get rank 1 and 2 pest killing spell for 1000 coins in golem court hope that helps :(
goulish wisps are pest so there bad there rank two so it would be best to be prepared they fly around your plant. idk if its some kind of bug remember there evil and can be kept away by bug zapper. it looks like it be sucking something from plants. if you see something red flying around your plant thats it. idk maybe its a bug that rise from the dead it has the word goul