Although the film makes extensive use of CGI effects for many of the scenes, some of the shots where Harold appears to draw in mid air were actually done with Harold (Zachary Levi) drawing on a sheet of glass placed between him and the camera.
Jemaine Clement previously worked with director Carlos Saldanha on 20th Century Fox and Blue Sky Studios' Rio duology as the voice of Nigel the Cockatoo.
Originally intended as a fully CGI film by Sony Pictures Animation, but instead became a live action/animation hybrid film with the animation scenes not being done by any studio of Columbia's in particular, with 7 VFX companies from around the world with the visual effects.
This is the first feature length film with major traditional animation to not be based off already existing animated media under the same format/continuity since The Princess and the Frog (2009), released 15 years prior.
Columbia Pictures' first major live action/animation hybrid film, as well as the first one of their's to be majorly traditionally animated in any way since Eight Crazy Nights (2002), released 22 years prior.