High society art critic Anthony Haden-Guest is throwing the sketchbook — and a massive lawsuit — at jet-setting fashionista Libbie Mugrabi, accusing her of holding nearly 100 of his cartoons and scribbles hostage in her Southampton estate. The legendary 89-year-old British-American art critic and cartoonist filed a Manhattan Supreme Court complaint, demanding the immediate return of 97 “original drawings and cartoons” he claims Mugrabi has been “wrongfully” displaying on her walls for 15 years.