After half a year, it turned into a Himalayan legend (4)
I believe the answer is:
yeti
'a himalayan legend' is the definition.
(I've seen this before)
'after half a year it turned' is the wordplay.
'after' is a charade indicator (letters next to each other).
'half a' suggests halving the letters.
'turned' is a reversal indicator.
'it' in reverse letter order is 'ti'.
'year' halved is 'ye'.
'ye'+'ti' is 'YETI'.
'into' acts as a link.
(Other definitions for yeti that I've seen before include "hairy thing proving elusive" , "Tibetan wild man" , "Anthropoid cryptid" , "folk regard it as a creature of legend" , "... and creature supposedly there" .)