I've had an issue since druids first recieved animal companions that my players (and sometimes I) would like an animal companion that doesn't fir on the chart. The animals in question aren't left off the charts because they're stronger than normal (that's easy to solve, just add it to the "tougher" charts.) Instead, they're much weaker than the standard animal companion. Such animals might be the equivelant (stat-wise) of a domestic cat or a bat. (We made stat blocs for skunks, foxes, and a few other animals that fit about that CR level.)
If a druid in your campaign wanted to play a druid with such a companion, how would you handle this? I see 4 options, but would be glad to hear others...
1) Allow the animal and play it as a normal companion from the standard chart.
"If they choose a weaker animal, fine. It's their right to sacrifice game-play for flavor."
2) Allow the animal as though it were on a new chart that treated the companions on that chart as though their druid were X levels higher than they are. Sort of in the style of 3.X companions.
"Sure that animal is ok. And, if stronger animals are treated like the druid is of lower level, weaker animals are treated like the druid is of higher level."
3) Allow the animal companion, but first advance that specific animal to be roughly equivelant to other animal companions, in the same way that the PF Tiger animal companion is weaker (at level 1) than the Bestiary Tiger.
"There's a reason druids don't normally choose that animal as a companion, so only a special individual of that species will do."
4) Flat refusal to allow such an animal as a companion.
"Those animals really are too weak to be companions. They're more more like...familiars. Perhaps you should choose something else?"
Any thoughts?
The game is designed to allow sub-optimal choices. As Monte says, "the game lets you eat rocks, it doesn't make them *tasty* rocks, but you can still eat them."