<Li> Casey Cott as Kevin Keller: An openly gay high school student who is friends with Archie, Betty and Veronica and is the son of Riverdale's sheriff . Cott was promoted to series regular in the second season . </Li> <Li> Skeet Ulrich as Forsythe "F.P." Jones II: Jughead's estranged father and the leader of the Southside Serpents, a gang of criminals that live and operate on the fringes of Riverdale . Ulrich was promoted to series regular in the second season . </Li> <Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> <Th_colspan="2"> Nielsen ratings </Th> </Tr> <Tr> <Th> First aired </Th> <Th> Last aired </Th> <Th> Rank </Th> <Th> Average viewers (in millions inc . DVR) </Th> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 13 </Td> <Td_colspan="1"> January 26, 2017 (2017 - 01 - 26) </Td> <Td> May 11, 2017 (2017 - 05 - 11) </Td> <Td> 154 </Td> <Td> 1.69 </Td> </Tr> <Tr> <Td> </Td> <Td_colspan="1"> </Td> <Td_colspan="2"> 22 </Td> <Td_colspan="1"> October 11, 2017 (2017 - 10 - 11) </Td> <Td> May 16, 2018 (2018 - 05 - 16) </Td> <Td> TBA </Td> <Td> TBA </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Season </Th> <Th_colspan="2"> Episodes </Th> <Th_colspan="2"> Originally aired </Th> <Th_colspan="2"> Nielsen ratings </Th> </Tr>

How many episodes are there in season 1 of riverdale