The last thing to give you warts? (5)
I believe the answer is:
straw
'the last thing' is the definition.
(I've seen this in another clue)
'give you warts?' is the wordplay.
'warts' can be anagrammed to 'STRAW'.
However, I'm not sure how this is indicated.
'to' is the link.
Can you help me to learn more?
(Other definitions for straw that I've seen before include "Thin tube; yellow" , "Thatching material" , "Dried stalks; yellow" , "corny stuff" , "politician" .)