Hello, I need help in understanding the grammatical structure of this sentence

I agree with the comment by @Ram Pillai.

What may be puzzling to you is the verb-subject inversion. Usually in a statement in English, we would say, "creatures crawl", not "crawl creatures". In everyday English, this sentence would be easier to understand if it were

Scattered among the leaves, we can see creatures (called Zeepers) that are half insect, half animal.

or

Scattered among the leaves, are creatures (called Zeepers), that are half insect, half animal.

The author uses what is called poetic licence, to give the verb "crawl" a double purpose. (1) it tells us that the creatures exist, i.e. they "are" and (2) it tells us that they crawl.

The style of the sentence is somewhat poetic and cleverly written.

Here's a paraphrase in more prosaic language

Scattered among the leaves, creatures crawl. They are called Zeepers and are half insect, half animal.

or

Creatures called Zeepers (that are half insect, half animal) crawl among the leaves. They are scattered among the leaves.

As you can see, the paraphrases do not flow as well as the original.