the front (George side) of the one-dollar bill, in the upper right-hand
corner sitting just to the upper-left of the number 1 is
a spider. A magnifying glass may be necessary to see it clearly.
It's also claimed that it's an owl, the icon of Bohemian
Grove* and therefore carries some hidden message.
It's looks more
like a spider to me, which makes sense as the bill is covered in
spiderweb-like lines (probably an early anti-counterfeiting technique).
Also, notice the delicate shading on the leaves. I'd say the artist
had a sense of humor and decided to create an early Easter
egg considering the hours that must have gone into drawing
the template for the bill.