there used to be 13 zodiac signs. and at roughly 2000 years each, fit within the approx 26000 yr Great Year nicely

there were 13 months in the year, of 29 days each (nearly a lunar month) . this gave 364 days.

the bullshit bible story of Judas is actually the allegorical story of how the calendar was to be forever changed from 13 months , to the now standard 12 month zodiac

so to answer the question - i am going with the sign that Judas represented to be the worst one, now can you locate between which two existing constellations that would be? think hard...