Dismas and Gestas
The names of the thieves crucified with Christ appear in the apocryphal Gospel of Nicodemus, the Acts of Pilate.
Book IX:5 reads
They are not unknown in the Orthodox tradition, where larger icons of the Crucifixion can show two crosses flanking Christ's.
According to tradition, Dismas, on Christ's right, repents and eventually joins Christ in Heaven, while Gestas blasphemes and ends up in Hell. At the moment of Christ's passing, he writhes in agony and his feet jerk, pulling the lowest crossbar askew. On the traditional Russian Orthodox cross, the lowest crossbar is at an angle, with the right side up (Dismas went to Heaven) and the left side down (Gestas went to Hell).