|Aliases||"Yani the Yanitor"|
|Interests||Cleaning, His wife, Revenge|
|First Appearance||Trapped with a Vengance|
|Voiced By||Tom Kenny|
Yani is the janitor of Dexter's school. He and his wife seem to be of Russian/Swedish origin due to his stereotypical Swedish accent and overall shape and features.
Due to Dee Dee being a constant nuisance to Dexter at home, Dexter prefers to do his experiments at school where it's quiet. However, he often overstays his welcome and leaves school at a very late hour, along with leaving an immense mess which Yani must clean up.
This causes Yani much misfortune, as working until late night causes him to arrive home at a late hour, which in turn causes him to accidentally wake his wife and she proceeds to unleash her fury on him. Having grown tired of Dexter's constant unintentional torment, he decides to trap Dexter in the school so he won't make it home on time to save his Laboratory from a laser wielding Dee Dee, which Yani was unaware about. Yani also fell for the fire alarm part so that Dexter could crawl through the vault. Luckily, his plan was broken by Yani's wife, with her finding him in the building, causing Yani to surrender and never trap Dexter with a vengeance ever again.
- It is unknown what happened to him after the events of "Trapped with a vengance", as he don't make any other appearance after this episode. But considering that he commited several crimes in this episode, as kidnapping to trapped dexter in the school against his own will, and he don't have qualms in punch dexter, commiting physical aggresion against a child, is possible that dexter ,off screen, accuse him with his parents and with the principal of the school, causing that he was fired and possibly arrested for commited this crimes.