The hippo Garcia and Callahan talks about is real. Her name is Jessica and she lives in Hoedspruit, South Africa.
This episode was 10.1 which aired on 10/1.
Kerr Smith (Frank Cowles) and Meredith Monroe (Haley Hotchner) played brother and sister on Dawson's Creek (1998).
Jennifer Love Hewitt (Kate Callahan) and Hailey Sole (Meg Callahan) have also appeared together in Ghost Whisperer (2005).
Kerr Smith (Frank Cowles) appeared in Final Destination (2000), while A.J. Cook appeared in Final Destination 2 (2003).