Prepare citrus slaw by combining all ingredients in a small mixing bowl. Set aside.
Prepare chipotle mayo by combining all ingredients in a small mixing bowl. Set aside.
Slice cod into 1x2 inch pieces. Pat dry with a paper towel. Set aside.
Prepare batter by combining flour, panko bread crumbs, and seasonings in a medium mixing bowl. Stir in beer; mix until no clumps remain.
Pour canola oil into a medium skillet, filling it about 1 inch deep. Heat on medium-high to 350°.
Working in small batches, dip fish into batter. Add battered fish to hot oil. Fry for 2 minutes on each side or until internal temperature reaches 145°F.
Remove fish from oil and place on a wire rack. Continue until all fish is fried.
Heat tortillas as desired. Assemble tacos by adding fish, citrus slaw, and sliced avocado to tortillas. Top with sauce and additional cilantro, as desired.