That time a retired pope and his wife got into a knife-fight with his successor: [View all]

http://www.cracked.com/article_26175_theres-secret-second-and-evil-catholic-church.html

TL;DR:

In 1968, four girls in Spain witnessed a miracle. Clemente Dominguez y Gomez used that as a pretext to found a cult, the true catholic church, because the actual catholic church was too progressive to his taste.

In 1978, Pope Paul VI of the real catholic church died and Gomez declared himself Pope Gregory XVII. (The catholic church somehow did not care.)

Gregory XVII excommunicated Pope John Paul II, canonized fascist dictator Franco and predicted that the Anti-Christ will be born in 2000 and enter public life in 2030.

From 2005 to 2011 the cult had Pope Peter II.

His successor, Pope Gregory XVIII, stayed at the job for a while, then retired, got married, and in 2018 he decided to break into the cult's basilica to rob it. He threatened his successor Pope Peter III with a knife, a fight broke out and Gregory XVIII was wounded, taken to hospital by an ambulance and ultimately arrested.
https://magnuslundberg.net/2018/06/14/ex-pope-and-wife-attempt-to-rob-basilica/