Approaches new terrors that need no introduction (5)
I believe the answer is:
nears
'approaches new terrors that need' is the definition.
'nears' can be an answer for 'approaches' (I've seen this before). I'm not sure about the remainder of the definition.
'no introduction' is the wordplay.
'no' becomes 'n' (common abbreviation y/n).
'introduction' becomes 'ears' (I can't explain this - if you can you should believe this answer much more).
'n'+'ears'='NEARS'
Can you help me to learn more?
(Other definitions for nears that I've seen before include "Moves closer to" , "advances" , "Approaches - snare (anag)" , "Draws close" , "Saner (anag.)" .)