Jamieson, Fausset and Brown on Isaiah 59:5

5. cockatrice--probably the basilisk serpent, cerastes. Instead of crushing evil in the egg, they foster it.

spider's web--This refers not to the spider's web being made to entrap, but to its thinness, as contrasted with substantial "garments," as Is 59:6 shows. Their works are vain and transitory (Job 8:14; Pr 11:18).

eateth ... their eggs--he who partakes in their plans, or has anything to do with them, finds them pestiferous.

that which is crushed--The egg, when it is broken, breaketh out as a viper; their plans, however specious in their undeveloped form like the egg, when developed, are found pernicious. Though the viper is viviparous (from which "vi-per" is derived), yet during gestation, the young are included in eggs, which break at the birth [Bochart]; however, metaphors often combine things without representing everything to the life.