The Pandavas were exiled for 12 years plus a 13th year that they had to spend undetected. If they were recognized, they would have to remain in exile for another 12 years. In that 13th year they worked under the following names and professions at the court of king Virata.
Draupadi as Malini, she was the lady’s maid.
Arjuna as Brihannala, he teached the princesses singing and dancing.
Bhima as Ballava, he was a cook.
Nakula as Granthika, he took care of the horses.
Sahadeva as Arishtanemi, he took care of the cows.
Yudhishthira as Kankubhattu, he was advisor to Virata.