(havent seen agu too much so this might already be mentioned in the show but) do you have any thoughts about harolds parents? like what they might be like and how they interact or affect harold himself?
yeah, harold's parents aren't ever shown in agu. that's probably the biggest thing that sets him apart from the main rugrats, that his parents aren't actual characters but just... concepts.
we were given some visuals outside of agu at least. his mom appears in rugrats, dropping him off for the first day of preschool.
and his dad appears in pre-school daze (the series), by showing up for the class play episode.
their professions are known. in rugrats, harold says his dad is a firefighter. in agu, harold says his mom is a mechanical engineer.
his family is implied to be well off. in rugrats, charlotte tells angelica that she set her up a playdate with harold because he has "very well-connected parents" (and in the end, harold says their mommies have become friends, so they're going to have lots of playdates. :)) and then in agu we see the exterior of his house, which looks like this:
which leads me to the headcanon that harold has access to financial wealth, which he uses to spoil angelica. perhaps his parents enable him in certain ways, similarly as angelica's parents do for her.
harold doesn't mention his parents much, but when he does, they seem to be caring figures he has a positive relationship with. there's nothing that would imply mistreatment and i wouldn't want to project that idea on him. but that being said, i think there's some room for grey area. like, his parents may be loving, but work may take them away often, so he could have still experienced unwillful neglect that led to increased attachment anxiety.
i kinda do have that headcanon in my mind, that perhaps harold was lonelier than other kids (even if his parents were actively present), especially since i headcanon him as an only child. perhaps him not being exposed much to other kids prior to preschool could explain why harold instantly clung to angelica, and susie to a lesser degree; they were the first other kids to give him acknowledgement.
i will say, i like that harold's parents are hardly relevant to his story, because fiction that focuses on parent-child relationships can make me sad and uncomfortable (especially if i relate too much to the child character). i guess that's a reason why im mostly tunnel visioned for just harold out of everything else in this franchise; the lack of parental involvement in his narrative is a relief.