unaware that it 's the butt of its own joke 
(ROOT (ADJP (JJ unaware) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ 's) (NP (NP (DT the) (NN butt)) (PP (IN of) (NP (PRP$ its) (JJ own) (NN joke)))))))))
(ROOT (ADJP (JJ ) (SBAR (IN ) (S (NP (PRP )) (VP (VBZ ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (JJ ) (NN )))))))))