In console emacs, the point becomes more than one character wide almost at random.
Even stranger, it acts as through the leading whitespace is the same color as the point. That is, if there is more than one leading space, the large point remains where it is rather than returning to the previous line, so it doesn't fully behave like a large point.
On the other hand, if I switch focus to another program, the point will look like wide hollow box. I'll try to illustrate how it looks with Unicode:
Focused:
██████ <-- Like point, but wider.
Unfocused:
[ ] <-- Fully-enclosed hollow box, like regular terminal cursor when unfocused.
I could only really reproduce the behavior by pressing space multiple times, and the point would become 2 wide every 4-5 spaces. It also occurs sporadically after pressing Tab, adding, and then deleting a character.
Please let me know if there is any other info that may be relevant or to somehow elaborate, since I have no clue what might be affecting emacs like this.
I found a solution from an ArchLinux forum thread.
To easily fix, either add the switch +ptab when starting urxvt or add urxvt*pastableTabs: false to your .Xresources.