Eggshell skull

An eggshell is often used as a visual metaphor for the thin skull rule.

The eggshell skull rule (also thin skull rule, papier-mâché-plaintiff rule, or talem qualem rule) is a well-established legal doctrine in common law, used in some tort law systems, with a similar doctrine applicable to criminal law. The rule states that, in a tort case, the unexpected frailty of the injured person is not a valid defense to the seriousness of any injury caused to them.