Mysterious plant

[Haru]

Hello,
I would like to ask for help with identification of one mysterious plant.
We found a strange plant which was growing next to other flowers. We took care of it because we thought it is a cucumber but it does no longer look like one. I am really curious what it could be so could you help me, please?
(thank you in advance)

 

[Chuck]

Hello,
I would like to ask for help with identification of one mysterious plant.
We found a strange plant which was growing next to other flowers. We took care of it because we thought it is a cucumber but it does no longer look like one. I am really curious what it could be so could you help me, please?
(thank you in advance)

It's some variety of watermelon.

 

[Haru]

It's some variety of watermelon.

Thank you very much. I am looking forward to see it grow.