idk if he'd be a clone since his mom triple threat calls him her miracle water baby. sounds like he was born. maybe jonas' "potent science" includes in vitro fertilization though.
theres, of course, dr quymn too. uncle vatred could be a failed super soldier clone of rusty. i forget who i'm forgetting.
I literally just edited my post scratching the clone idea when you replied. I do think that anyone with red hair is a likely candidate for being a clone or bastard. I never thought about vatred being one, but I guess that could explain his unnatural attraction to the venture children
in the episode where jonas junior is having a party in the museum on spiderskull island, there are 2 adult st clouds and a possible child st cloud. i suspect his parents bought a cloner from jonas sr and is another possible bastard. his rich parents aren't as big on letting society tell them to not pump out multiple surviving versions of their son, and they like having a little st cloud around as an accessory.
I'm kind of expecting Billy to turn out to be a botched clone of Rusty.
Edit I just remembered how much he looks like his mom and how she is exactly the kind of girl to put out to Jonas. Scratch my clone idea.