Simple Method

The easiest way to formulate a familiar when there aren’t already stats for the creature you’re looking for is to examine the list and find the animal closest to the one you have in mind. You can then simply use the statistics of the existing animal as those for your desired familiar. This ensures that the familiar is balanced, and it doesn’t require you or the GM to tinker with the animal’s statistics.

When approximating familiars, the most important thing to realize is that a given familiar’s statistics can be used to represent a wide variety of other creatures of the same creature type, not just that species. For example, the rat is a small, agile mammal, so it’s a reasonable leap to use its statistics to represent a mouse, shrew, or other similar small mammal. Conversely, using the stats for a bat to represent a flying fish, despite some similarities, is probably suboptimal. Consider some of the Advanced Method options for making more significant adjustments to a creature.

The Approximate Familiars chart provides a list of the animal familiars most suitable for approximating other types of creatures, suggestions on what those creatures might be, and the sources of the statistics for the base animals. The suggestions listed beside each entry are not exhaustive, of course; they are merely there as guidelines to help you devise the perfect familiar for your character.