I have been making my own organic soil using kitchen waste since last winter.
To my surprise, I found this little plant in the same pot for green pepper.
My friend advised me to transfer this little plant into another container in order to let the green pepper grows well.
I did as I was told, however I still do not know what kind of plant it is exactly.
My friend told me it looks like pumpkin.
I am going to wait patiently to let it grow. This little plant cheers me up whenever I look at it.