The Donkey
Gadrabha Sutta  (AN 3:83)

“Monks, it is just as if a donkey were following right after a herd of cattle, saying, ‘I too am a cow! I too am a cow!’ Its color is not that of a cow, its voice is not that of a cow, its hoof is not that of a cow, and yet it still keeps following right after the herd of cattle, saying, ‘I too am a cow! I too am a cow!’ In the same way, there is the case where a certain monk follows right after the Saṅgha of monks, saying, ‘I too am a monk! I too am a monk!’ He doesn’t have the other monks’ desire for undertaking the training in heightened virtue, doesn’t have their desire for undertaking the training in heightened mind [concentration], doesn’t have their desire for undertaking the training in heightened discernment, and yet he still keeps following right after the Saṅgha of monks, saying, ‘I too am a monk! I too am a monk!’

“So you should train yourselves: ‘Strong will be our desire for undertaking the training in heightened virtue; strong will be our desire for undertaking the training in heightened mind; strong will be our desire for undertaking the training in heightened discernment.’ That is how you should train yourselves.”

See also: AN 3:90—91; AN 4:178