Drawing Michelangelo finally put into box (7)
I believe the answer is:
cartoon
'drawing' is the definition.
(I've seen this before)
'michelangelo finally put into box' is the wordplay.
'finally' suggests the final letters.
'put into' means one lot of letters goes inside another.
'box' becomes 'carton' (carton is a kind of box).
The final letter of 'michelangelo' is 'o'.
'o' placed within 'carton' is 'CARTOON'.
(Other definitions for cartoon that I've seen before include "Humorous or satirical drawing" , "Humorous sketch" , "Comic strip" , "Drawing, maybe satirical" , "Jokey drawing" .)