In a kind of rhythmic fashion, an animal climbing upon another of its kind — very absorbing! (8)
I believe the answer is:
staccato
'in' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for staccato that I've seen before include "With every note detached in cats's coat" , "Disjointed, not smooth and flowing" , "Musically sharp and disconnected as in toccatas" , "With notes sharply separated (music)" , "In music, in a sharp disconnected manner" .)