This work describes mechanical behavior of a high-strength hydrogel composite relative to costal cartilage. The materials are analyzed for monotonic ultimate tensile strength (UTS) with differing flaws that represent extreme differences in local stress concentration and distribution. Selected hydrogel and cartilage samples are investigated for fatigue analysis via cyclic loading. Synthetic hydrogel samples are more sensitive toward sharp cracks, while cartilage samples are more sensitive toward cylindrical holes in fatigue. This work represents a unique tensile fatigue approach in studying a high-strength soft material and porcine costal cartilage with and without extreme defects.