Mountain cat almost catches a llama-like animal (6)
I believe the answer is:
alpaca
'llama-like animal' is the definition.
(alpacas are similar to llamas)
'mountain cat almost catches a' is the wordplay.
'mountain' becomes 'alp' (the Alps are a mountain range).
'almost' means to remove the last letter (most of the word but not all of it).
'catches' means one lot of letters goes inside another.
'cat' with its final letter removed is 'ca'.
'alp'+'ca'='alpca'
'alpca' placed around 'a' is 'ALPACA'.
(Other definitions for alpaca that I've seen before include "South American animal" , "(Woollen cloth from) relative of llama" , "woollen fabric" , "Wool of S American lama" , "Type of wool" .)