It's actually a garden tool!

So I was thinking about Chara's dagger and why it is 'worn'. Since I'm sure Chara loves flowers and by expansion gardening a lot, I came to the conclusion that they had used it for gardening. >= DI love the idea that they helped Asgore in the garden using that knife to cut plants and vines. I also think that this tool was originally Asgore's but since Chara liked it so much he decided to give it to them (that's why it's wrapped in a present box) ---Undertale by Toby Fox