Avodah Zarah 1:6-7

Avodah Zara 1:6

In a place where the practice is to sell small animals to idolators, one may do so; in a place where the practice is not to do so, one may not. One may not sell them large animals, calves or foals in any location, whether these animals are unimpaired or damaged. Rabbi Yehuda permits selling them a damaged animal; Ben Beseira permits selling them a horse.

Avodah Zara 1:7

It is forbidden to sell them bears, lions or anything else that may pose a public hazard. One may not partner with them to build a basilica, a scaffold, a stadium, or a tower but it is permitted to partner with them to build public and private bathhouses. Once they reach the dome where they will place the bathhouse idol, one may no longer build with them.