It is part of the 25 sub-set card list, so it will be a little harder to pull than the original 25 cards
It is all down to the cycling effect it has that pushes this so well
Removing five defense counters from Invasion of Tarkir exiles it, enabling you to cast it transformed into a 4/4 Dragon with flying, trample, and an ability that deals two damage to any target whenever a Dragon you control attacks
Slimefoot, the Stowaway Slimefoot, the Stowaway snuck into the top 10 and is interestingly only ever really used for Saproling-based decks
We will be meeting Lukas with the Prize Cube ahead of the event in Las Vegas, where he will conduct a final grading on site
Keep in mind that were not talking about creatures that will gain you life through other means, like entering the battlefield or death triggers, just those with the lifelink keyword