Based on the 'Here Comes the Grump' animated cartoon series produced by DePatie-Freleng Enterprises and aired on NBC from 1969 to 1970.
Anima Estudios' first co-production with London-based Prime Focus World. The two companies will collaborate again in Monster Zone (2020).
At 34:15 minutes, Princess Dawn, Terry and Bip pass by a mirror on the floor. Their reflection is from the 1969's cartoon.
While the film was shown in the 2.39:1 aspect ratio internationally, it was shown in the 1.85:1 aspect ratio format in Mexico.
Not only is this the first British-Mexican animated film co-production, it is also the first animated feature to be done entirely by Prime Focus World after years of providing visual effects work to many blockbuster movies.