How does 67P rotate?
Looking at this site, there is a table, which has some information.


  Rotation period: 12.4043 ± 0.0007 * hours    


It also rotates around a fixed axis


  recent observations suggest that the axis is tilted about 40 degrees


There are actually only two objects known to rotate chaotically in the solar system - one is Saturn's moon Hyperion, and the other is a small asteroid called 4179 Toutatis (source: this link from Guinness World Records)