that starts out like heathers , then becomes bring it on , then becomes unwatchable 
(ROOT (SBAR (WHNP (DT that)) (S (VP (VP (VBZ starts) (PRT (RP out)) (PP (IN like) (NP (NNS heathers)))) (, ,) (ADVP (RB then)) (VP (VBZ becomes) (S (VP (VB bring) (NP (PRP it)) (PRT (RP on))))) (, ,) (ADVP (RB then)) (VP (VBZ becomes) (ADJP (JJ unwatchable)))))))
(ROOT (SBAR (WHNP (DT )) (S (VP (VP (VBZ ) (PRT (RP )) (PP (IN ) (NP (NNS )))) (, ) (ADVP (RB )) (VP (VBZ ) (S (VP (VB ) (NP (PRP )) (PRT (RP ))))) (, ) (ADVP (RB )) (VP (VBZ ) (ADJP (JJ )))))))