St Paisios had a pet frog, Bayum, and together they would "sing psalms" and do prostations together in front of a large wooden cross every evening.
Met. Amfilohije, then hieromonk at Athos, confirms this :
Then Elder Paisios said to me: "Are you a monk? Then, be obedient. Here, my Bayum is more obedient than you."
I asked him in surprise who Bayum was, because I knew that there was not a single person there. Then he showed me a rose bush, which he planted there. He went there, stood in front of the bush and said:
"Come, Bayum, show this distrustful Amfilohije what true obedience is."
As the ground around the bush was freshly dug and soft, it began to rise and suddenly a frog came out.
Then he said to the frog: "Now return, Bayum, to your place, and in the evening go to pray."
I was surprised and asked him how Bayum was praying. He explained to me that the frog goes in front of a large wooden cross in the evening, which was there, to "sing psalms".
On the same day, as soon as the sun set I saw a frog in front of the cross croaking: "Krekeke, krekeke".
He came jumping and stood next to the Elder.
Doing his prostrations, the Elder would get up, and the frog would get up too, and they did their prostrations before the Cross of Christ.