Question: Is there any term (a diminutive) in English for "little body"? I suppose that the forms such as "bodylet" and "bodyling" are utterly incorrect.

Here is the context: "Graving snow caressing the **little body** dismembered".

Answer: 
While not a noun, the adjective **[petite](http://www.oxforddictionaries.com/us/definition/american_english/petite)** is often used to mean

> 
> (Of a woman) having a small and attractively dainty build:
>  *she was petite and vivacious* [ODO]
> 
> 
> 

Note that is is almost always applied to women or girls, and is generally positive in tone.

The term **[bantam](http://www.collinsdictionary.com/dictionary/english/bantam)** means

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> a small but aggressive person [Collins English Dictionary]
> 
> 
> 

This generally refers to the entire person, including his attitude, not just his body.

Similarly, **[Lilliputian](http://www.oxforddictionaries.com/us/definition/american_english/Lilliputian)** (with or without capitalization) means

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> A trivial or very small person or thing. [ODO]
> 
> 
> 

Again, there is a tonal connotation, in this case suggesting *unimportant*.

The term **midget** has a long and checkered history. Currently it is usually characterized as objectionable. The [ODO](http://www.oxforddictionaries.com/us/definition/american_english/midget) labels its definition as *offensive*

> 
> An extremely or unusually small person.
> 
> 
> 

A further discussion of the term and its pejorative nature can be found in this [Wikipedia article](http://en.wikipedia.org/wiki/Midget).
I would try ectomorphic - which describes the physical body structure:

> 
> ec·to·mor·phic /ˌɛktəˈmɔrfɪk/ [ek-tuh-mawr-fik] [source][1](http://dictionary.reference.com/browse/ectomorphic)
> 
> 
> adjective 
> 
> 
> Having a thin body build, roughly characterized by the
>  relative prominence of structures developed from the embryonic
>  ectoderm (contrasted with endomorphic, mesomorphic ). 
> 
> 
> Origin: 1935–40;
>  ecto- + -morphic
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> 
>