At some point in a bullfrog tadpole's life transition or transformation to a full fledgling frog, the flavor of them has to change dramatically. The distasteful flavor change I think is a very gradual one from bad to tasty and very similar to the morphological change from full tadpole to full frog, The tail is the last main outward structural feature to disappear. IMO near this 'loss of tail' time is when the final amount of bad flavor also disappears. Thus when the new immature frog starts hopping around, it has a new body flavor similar to 'chicken' and it is a very welcome guest to all dinner tables.