A Paribbājaka. Once when he was staying near Sāvatthi in Mallikā's pleasance at the Samayappavādaka hall, the carpenter (thapati), Pañcakanga, on his way to see the Buddha, visited him and had a conversation with him, which conversation Pañcakanga later reported to the Buddha (M.ii.22f). The details are given in the Samana-Mandikā Sutta.
According to Buddhaghosa (MA.ii.710), the Paribbājaka's original name was Sumana, but he was called Uggāhamāna because he had the ability to learn a few things (because he was always learning things?).
Chalmers (Further Dialogues ii.12n) suggests that perhaps his mother's name was originally Sumanā and that it was altered to Samanā, just as there is the further tendency to read mundikā for the second part, in order to make her name mean "shaveling recluse" on familiar Pāli analogy.