I wanted to create a separate object which is in the shape shown in the picture. How could I do this? I cannot just scale the original object up as the outline will be uneven.

The file is attached if needed.

I would

• select both paths duplicate and do path > union
• Then set fill to white and send the result to bottom
• Then add it an offset live path effect. Once satisfied with the lpe, you can finally do path > object to path to cook the effect. 

The "eyes" and the small gap between the two serpents should disappear when offsetting.

That worked great, thank you!