Familiars are typically obtained via the find familiar spell.

Stats listed in the find familiar spell description are used. Stats not provided are taken from a monster book.

Often, stats for a familiar are found in the MM2, rather than the MM. Rules listed under find familiar always trump the monster books.

Scouting with a flying familiar such as a hawk grants the familiar a special surprise check with an encounter distance greater than normal. Hawks multiply the encounter distance by 10; the DM will adjust this multiplier upward or downward for scouts of different perceptive abilities.^Ex1)