A dad received a school letter about his son's imaginary friend. And it is pure gold.

Any parent with a school-aged child is no stranger to their kid pulling out a new note from a teacher every second day.

But one dad received a note about his son that was so bizarre and hilarious he just had to share.

Paul Hunt posted an image of the note online, with the caption, “This letter, that was sent home from school today, is the funniest thing I’ve ever read.”

“Although this is not a behaviour letter as such, I am writing to inform you of something that has come to our attention and that you may wish to discuss further with [your son],” the letter begins.

It seems Paul’s son and his friends like to play make-believe in the playground, giving each other funny names. Which is totally normal, because they are kids, obviously.

kids laughing
Funny names are funny, right kids? Image via iStock.

The thing that's not so normal? The names the children are using during playtime.

"It has come to out attention that one of the characters has the name 'Wildo the Dildo'," the note continues.

"This has, I am sure you can understand, raised some concerns with us.

"None of the children said they knew what it meant, but were aware it was an inappropriate word to be using. One of the children said they picked up the word on the playground, so we will be following this up further."

What's worse than notes from teachers? Lunchbox politics.

Fellow Twitter users had some not-so-helpful suggestions for how Paul should respond to the unexpected note.

"Write back and ask what a dildo is," one suggested, while another said, "Enter Wildo into the competition for the London 2017 mascot."

Whatever the outcome, here's hoping Wildo is left out of the next playtime at school.