Suggestions by @bgp

Shrek and Donkey

as Po in Kung Fu Panda if Fictional Characters

Lord Maximus Farquaad

as Tai Lung in Kung Fu Panda if Fictional Characters

Humphrey (Alpha and Omega)

as Master Shifu in Kung Fu Panda if Fictional Characters

Cameron Diaz

as Lilly in Alpha and Omega (Live Action Remake)

Queen Latifah

as Lilly in Alpha and Omega (Live Action Remake)

Angelina Jolie

as Lilly in Alpha and Omega (Live Action Remake)

Kate Higgins

as Lilly in Alpha and Omega (Live Action Remake)

Ginnifer Goodwin

as Lilly in Alpha and Omega (Live Action Remake)

Fred Tatasciore

as Garth in Alpha and Omega (Live Action Remake)

Louis C.K.

as Garth in Alpha and Omega (Live Action Remake)

Chris Hemsworth

as Garth in Alpha and Omega (Live Action Remake)

Josh Tomar

as Garth in Alpha and Omega (Live Action Remake)

Walt Dohrn

as Garth in Alpha and Omega (Live Action Remake)

Morgan Freeman

as Humphrey in Alpha and Omega (Live Action Remake)

Walt Dohrn

as Humphrey in Alpha and Omega (Live Action Remake)

Zoe Saldaña

as Kate in Alpha and Omega (Live Action Remake)

Amanda Bynes

as Kate in Alpha and Omega (Live Action Remake)

Ginnifer Goodwin

as Kate in Alpha and Omega (Live Action Remake)

Kate Higgins

as Kate in Alpha and Omega (Live Action Remake)

Molly Shannon

as Kate in Alpha and Omega (Live Action Remake)