Can leeches kill onions?
I’ve planted the middle (stalk) of an onion we used for cooking… then it grew its leaves. (are they called leaves?) However, every week or two, it seems to let a leaf wither, which didn’t really bother me since it still grows other new leaves… then one night, I used an old stem from another tree to remove something that looked like cat poop clinging on a leaf… when I checked the onion plant in the morning, that something I removed was no longer in the place where I put it, so my assumption that it was a leech is right… after a few more days, I finally touched a seemingly healthy leaf just to be surprised…it’s soft! should those leaves really just be soft?? I don’t want to check yet if there are worms or other pests inside my onion stalk…I don’t want to dig this early. could soft leaves mean my onion is unhealthy? or are they really just like that?…
btw, I’m in a tropical country… our plants don’t die out much in the cold seasons here…
to Billy Bob Canvey: you’re right! how could I have forgotten that leeches only feed on blood?! thanks for reminding. 
Leeches feed on blood, and as there is no blood in an onion the leech would not be interested. This could be a slug on your onion.
Billy Bob is right about leeches and slugs. Slugs and other pests don’t usually bother onions too much. They would rather eat less pungent plants. I wouldn’t worry about the leaves being soft. Onions are pretty tough plants. They are not easy to kill.