you 'd want to smash its face in 
(ROOT (S (NP (PRP you)) (VP (MD 'd) (VP (VB want) (S (VP (TO to) (VP (VB smash) (NP (PRP$ its) (NN face)) (PP (IN in)))))))))
(ROOT (S (NP (PRP )) (VP (MD ) (VP (VB ) (S (VP (TO ) (VP (VB ) (NP (PRP$ ) (NN )) (PP (IN )))))))))