&headcanon 01 - Vlad Masters is Danny Fenton's biological father.
âMaddie, you must be exhausted â carrying the weight of that mistake you made all those years ago.â
   â Vlad Masters, Maternal Instinct (S01E16)
To anyone else, this might feel like a throwaway line referring to Maddie's decision to pursue a relationship with Jack instead of Vlad, but I like to put more weight into it than that; I believe that Vlad could actually be referring to a night spent with Maddie fourteen years ago.
Why?
Aside from the phrasing, we know from Prisoners of Love (S01E08)Â that Maddie and Jack fighting or disagreeing isn't uncommon. Jack has even forgotten their anniversary every year for eighteen years, and every year (note:Â assumption) this happens, Maddie stays with her sister Alicia Walker in Spittoon, Arkansaw for a time to calm down. Jazz hardly bats an eyelash at this behaviour in the aforementioned episode; she's seen it more times than she can count up to now.
Did you know that Arkansaw is an unincorporated CDP in Wisconsin?Â
I don't believe it's too far of a stretch to assume that Maddie once, just once, spent her cool-down time with her college friend Vlad Masters. Even without taking her hurt emotions and doubts into account, Maddie demonstrates in Masters of All Time (S02E14) via the alternate timeline that she is (or has the capacity to be) attracted to Vlad - at least physically. She never loved him, however; it's clear that her heart still belongs to Jack despite her marriage to Vlad in this world.Â
Following that train of thought, a hurt, emotional woman alone with her old friend slash unlucky former love interest in Wisconsin on a disappointing anniversary might make a devastating mistake. It could happen to anyone. I don't doubt that Maddie loves Jack with all of her heart, but at that time she was angry with him and upset. She may have even convinced herself it never happened afterward, but when you get right down to it...
It's entirely possible that Vlad Masters is Daniel Fenton's father.
Other things of note:
Maddie's anxious smile and silence when Vlad flirts with her in Bitter Reunions (S01E107)
Vlad's complete and total lack of interest in Maddie's other child, Jasmine Fenton. This can, however, be chalked up to the absence of ghost powers in Jazz.
Vlad's insistence that Danny is more like him than he thinks.
Vlad had black hair and blue eyes - a shade closer to Danny's than Jack's - before the accident with the proto-portal (seen in Masters of All Time [S02E14])Â that gave him his ghost powers.Â
Danny's slight built, which is not unlike Vlad's. Jack Fenton is a mountain of a man, and Danny shows no sign of inheriting his height or bulk.
Danny's capacity to be a self-centered, manipulative jerk in need of an attitude/ego-adjustment.
It's possible that Maddie's night with Vlad helped foster his obsession with her.
Is it possible that Danny only survived his accident (noteworthy- this was a more powerful, more complete portal into the Ghost Zone) thanks to his half-ghost heritage?
