It is said that the prama earned its name from this fetish. In general, when Dentsewo celebrate Dentsefo memenda (Saturday), they say they are celebrating Petu. It is said that this fetish possessed one Kofi Eku to be its first osɔw (priest) and specified how it must be pacified and consecrated annually. The process involved taking the fetish to the Muni lagoon to be consecrated at midnight of Friday and brought back in a procession the next day; Saturday. This fetish specified the use of a yam meal, ɔtɔ to be prepared in the process. The celebration is started with the asafo elders taking the fetish Petu to the Muni lagoon at midnight and ensuring that the consecration is performed. By 8.00am in the morning, the asafomen with drumming join them and the fetish is carried by one of the priests clad in white calico at the waist.
The procession which starts from the lagoon area with a salvo of musketry being fired, drumming and singing of asafo war songs. The procession passes through the Muni flood area (Muni paaso) then to abosomba and along the main road to the Palace. At the junction to the Palace, the procession uses the Queen’s street to Penkye and then to Aboadze. At each road intersection they would stop to enable the priest offer libation to the gods and a salvo of musketry follow.
Then they move on. The fetish Petu is sent to the beach where it is made to touch the sea and then returned to the prama where the fetish is brought down and a ram slaughtered.
The yam meal prepared from the Muni lagoon is now sprinkled all over with parts of the slaughtered ram cut into tiny pieces. The rest is shared among the elders of the prama and the asafo. When all the processes are finished, the fetish is sent back to its shrine for keeps till the following year. People from all walks of life join the procession, singing and dancing to the Petu war songs. It is noted that three days after this there is high tide and during these days no one goes fishing till the tides subside. This is the Dentsefo memenda celebration.