Battus eracon, the west-Mexican swallowtail or Colima swallowtail, is a species of butterfly in the family Papilionidae.

[1][2] It is found in western Mexico where it is local and uncommon.

[3] The larvae feed on Aristolochia tentaculata.

The hindwing has a uniformly curved band of spots, placed about midway between the cell and the outer margin.

Under surface of the hindwing has red submarginal spots, each with a yellowish white dot at the outer side.