An elderly parishioner shocked cultural officials after she made a well-intended but unauthorised go at restoring the piece of art.
Ecce Homo (Behold the Man) by Elias Garcia Martinez has been inside the Sanctuary of Mercy Church near Zaragoza for over 100 years.
The lady - who is in her 80s - reportedly painted over it as it had degraded over the years due to moisture in the church.
The original painting of Jesus Christ has now been buried underneath the woman's childlike portrait, described as "a crayon sketch of a very hairy monkey in an ill-fitting tunic" by BBC News.
Art experts are now expected to decide how to attempt to restore the painting.
City councillor Juan Maria Ojeda said: "I think she had good intentions. Next week she will meet with a repairer and explain what kind of materials she used.
"If we can't fix it, we will probably cover the wall with a photo of the painting."
The painting is not said to be of any high value, but is known to be a treasured item for people in the local area.
The local artwork preservation centre had ironically just received a donation from the painter's granddaughter, which they had hoped to use on the fresco.
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Watch Mr Bean getting himself into a similar situation below. Coincidentally, the theme music to Mr Bean is translated as 'Behold the man who is a bean'.