@previous (B)
I've been wondering this myself, and I really can't get a read on Bert. As of now, I have three theories:
Your typical reptilian infiltrator is usually disguised as a sociable, likeable human. Obviously, because this makes it easier for them to gather information. Bert goes against this, and frequently acts in ways that make others dislike and insult him. So he might simply be a drunken human.
Second possibility: Bert is a reptilian spy, but is severely incompetent. There's a few signs that make me think this. The main one is the ellipsis abuse. The reptilian written language uses dots similar to our full stops to denote pitch. The meaning of words and phrases in the reptilian language can be slightly altered dependant on pitch, and it's mandatory to include those "pitch dots" extensively within reptilian writing. So it could be that Bert is a reptilian who hasn't learnt the language very well. On top of that, his choice of persona is telling. Reptilian society, unlike modern human society, greatly and uniformly reveres its nobility. So, from his point of view, his claims of being a "southern gentleman" seem like a good way to quickly gain respect. From the human point of view, he seems like a fool. Finally, his hamfisted attempts to flirt with female Minichanners might be a clumsy attempt to fufil the standing order for reptilian infiltrators to create half-breeds.
You may be wondering how such an incompetent reptilian would end up as a spy? It's possible that Bert, if a reptilian, is the son of a noble, who would have the influence to put one of his kids one-off a prestigious job even if they're not suited to it. His assignment would reflect this, since the reptilians rate Minichan as a low-priority target (even though they've assigned at least five infiltrators here which is odd).
Final possibility: Bert is a reptilian infiltrator, but is competent and working as intended. They don't do it often, but one trick the reptilians like to pull when multiple agents are infiltrating one place is to have one infiltrator behave in an annoying, unlikeable way. This then lets the other spies easily bond with humans over how stupid/annoying that "other human" is.
Anrway, reptilian or no, he is an odd sort.
(Edited 5 minutes later.)