The bulk update request #5386 is pending approval.

create alias eyes_popping_out (166) -> bulging_eyes (397)
create alias eyes_popping (0) -> bulging_eyes (397)
create implication bulging_eyes (397) -> eye_bulge (89)

Reason: Most people use the bulging_eyes tag for images where character's eyeballs are bulging out of their head. eye_bulge can be used as the singular variant. eye_pop can be used when the eyeball is fully out.

eye_bulge should alias to bulging_eyes instead, we don't need a singular and plural variant.

Also eye_pop seems ambiguous, could mean that the eyeball pops fully out of their head, or the eyeball itself explodes or bursts. Although for the 4 tags that uses it, it seems to be used in the former case.