Josh Radnor Ted Mosby Actor Jason Segel Marshall Erikson Actor Alyson Hannigan Lily Aldrin Actor Neil Patrick Harris Barney Stinson Actor Cobie Smulders Robin Sherbatsky Actor Bob Saget Narrator Alexis Denisof Sandy Rivers Guest Star Amy Acker Penelope Guest Star Robert Michael Morris Lou Guest Star David Henrie Son Guest Star Lyndsy Fonseca Daughter Guest Star Suzanne Ford Vet Guest Star Mark Gagliardi Quartet Leader Guest Star Carter Bays Executive Producer, Writer Craig Thomas Executive Producer, Writer Pamela Fryman Director