Best familiar for a broke apprentice

Esteemed elders, I seek your wisdom. I'm reaching the last stages of my apprenticeship (majoring in abjuration with a minor in conjuration), and I'm about ready to bind a familiar to my service. The problem is, while my master is great in knowledge, he is... lacking in generosity. What sort of creatures would be most useful as a familiar to a younger wizard aspirant with, shall we say... a paucity of resources to dedicate to the creature's wellbeing?