Octopus, when cooked properly, has a luxurious and meaty texture somewhat akin to scallop, but with slightly more chew. The flavor is unique, but mild, and hard to describe, like, "What does a mussel, oyster or clam taste like?" but otherwise reminiscent of "the sea". For comparison's sake, the best you can sum it up with is that it does not taste like squid, though that is a reasonable comparison for baby octopus. A lot will vary depending on expertise of the cook, cooking method, and size of the octopus.