Open and drain black beans and corn. Place them in a large mixing bowl.
Finely chop the entire bunch of cilantro (remove the steams), 3/4 of the red onion, all 4 tomatoes and serranos (remove the seeds - THEY ARE EXTREMELY HOT) and add the contents to the large mixing bowl.
Squeeze two limes over the salsa in the mixing bowl and stir.
Salt and pepper to taste, stir and place in the refrigerator for 1 hr (not required - just allows the flavors to really come out).
Slice 4-5 avocados into little squares and add them to the mix. Add additional salt as needed or preferred. Remember there is salt on the chips as well, so don't add to much salt to the salsa.