This is the Giant Mystery Snail (Pomacea bridgesii), nobody actually knows their name or too much about them because they really lean into the "mystery" thing!! This mysterious snail friend likes to hang out in your Pond and offer you videos to watch in exchange for rewards! You will be able to watch videos from level 4 onwards.
Ads may not always be available due to a number of factors like device type, platform, region etc. so if there aren't any videos to watch right now try coming back later to check in with your snail.