<Li> Bodhi Elfman as Peter Lewis / Mr. Scratch </Li> <Li> Aubrey Plaza as Cat Adams </Li> <P> Jennifer Love Hewitt left the show because of her pregnancy, and her character Kate Callahan, handed in her resignation at the end of the season ten finale, due to her pregnancy and decision to devote the next year to her baby . It was announced that Aisha Tyler will replace Hewitt in a recurring role as Dr. Tara Lewis . A.J. Cook revealed herself to be pregnant, and it was later revealed in the tenth season finale that her character Jennifer "JJ" Jareau was also pregnant . She did not appear in the first six episodes (except the season premiere). Showrunner Erica Messer expressed her desire about bringing back old characters from previous seasons, including Spencer Reid's mother played by Jane Lynch . Cook appears in the first episode "The Job" holding her sleeping baby Michael, played by Phoenix Andersen, her child in real life . </P> <P> According to Matthew Gray Gubler, he will be directing an episode in which another BAU member will be leaving the cast this season, that member being Derek Morgan (Shemar Moore). Shemar Moore left the show as Derek Morgan, which aired on March 23, 2016 . On February 10, 2016, it was announced that Paget Brewster would return as Emily Prentiss for one episode later in season 11 episode 19, titled "Tribute". The season ended on May 4, 2016, with the show's first cliffhanger finale since the fifth season . Messer said she felt it was time for another cliffhanger and thought that it served as a "really fun launch pad" into the twelfth season, which was officially ordered two days later . </P>

What episode does jj come back in season 11
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