PG | ★✩✩✩✩

My children have not come across Harold and his crayon and neither therefore had I before this latest vehicle for Shazam star Zachary Levi landed. This is a disadvantage when viewing a movie inspired by the American children’s books in which everything the eponymous baby draws (with the apparent skill of a seasoned draughtsman) comes to life. For you will need fathom-deep reserves of nostalgia and affection for the source material to make it through to the end of this film.

Harold lives in a 2D world conjured by his imagination and his crayon. For the purpose of this film however, the babe has grown into a curious man-child (a line-drawn version of Levi) who converses with the kindly and elderly voice of his creator, “old man”.

When the voice abruptly stops Harold and his animal friends Moose and Porcupine resolve to find its owner. Harold draws a door into the real world and so begins the quest to find the old man who, it emerges, is the late Crocket Johnson, creator of the original books.

Though Johnson died in 1975 the world in which Harold and his friends find themselves is the present one. With his default facial expression fixed to wide-eyed wonder Levi’s Harold and Lil Rel Howery’s Moose (now in human form) randomly hitch themselves to a widowed single mother (a laid-back Zooey Deschanel) and her young son who helps Harold on his quest to find the old man.

Lil Rel Howery (left), Benjamin Bottani (middle) and Zachary Levi

 Harold, Moose and Porcupine (who has her own equally inane subplot) do this with the intelligence of a bunch of parsley. Director Carlos Saldanha applies similar levels of insight to the storytelling. Thank goodness for the mildly amusing villain Gary (Jermaine Clement), a rejected wannabee fantasy novelist who has evil designs on Harold’s magic powers. However the whole witless thing feels as if were written by screenwriters David Guion and Michael Handelman in crayon.