There are accounts of sharks and squid engaging in combat, but it's uncommon and challenging to capture direct proof of such encounters. Sharks and squid are both formidable predators equipped with sharp teeth, and powerful tentacles. Here are some cases where sharks were found with evidence of squid encounters:

1. Scarred Shark: In 2014, a tiger shark was found with extensive scars and lacerations on its body, suggesting a battle with a giant squid. The shark's wounds were so severe that it had nearly killed the animal.

2. Squid beaks: Researchers and fishermen occasionally find large squid beaks embedded in the flesh of sharks, indicating a struggle or attempted predation by the squid.

3. Stomach Contents: In some instances, scientists have found undigested squid remains inside shark stomachs, suggesting a successful hunt.

4. Tooth Marks: Shark teeth marks have also been found on the bodies of giant squid that wash up on shore.

While these cases provide circumstantial evidence of shark-squid encounters, direct observations of their conflicts are rare due to the nature of their habitats and the low frequency of these interactions.