It only appears at Big the Cat's fishing levels in Sonic Adventure and usually weighs about 2000g. It is the only robot in Sonic Adventure that can not be destroyed, thus not containing animals. It usually appears in Twinkle Park and Emerald Coast. It is also seen in various pools for Big's missions in Sonic Adventure DX: Director's Cut.
The various missions that Big can find the E-28 Mecha Fish:
|14||I am the keeper of this hotel! Catch me if you can!||Station Square, between station entrance and underground parking lot.||Fish for the Mecha Fish in the hotel's pool.|
|29||I am the keeper of this canal! Catch me if you can!||Station Square, garden to the right of Town Hall where there will be an egg-shaped stone.||In the water way behind Twinkle Park elevator (just under where Tails can find the Jet Anklet), a Mecha Fish swims. Fish for it.|
|35||I am the keeper of this icy lake! Catch me if you can!||Mystic Ruins, In the caves leading to Mystic Ruins Garden, enter the caged Kiki cave, right behind the mound of dirt.||Fish for the Mecha Fish in the pool in the ice cave near the ladder to Icecap.|
|44||I am the keeper of this ship! Catch me if you can!||Egg Carrier, port side stern of the ship (very corner of the Egg Carrier).||Fish for Mecha Fish in Eggman's swimming pool.|