Im unsure if this is playable it a effectively 4 mana 2/5 taunt deathrattle summon a 2/1 taunt. we already know a 2/6 taunt isn't good enough and a 2/6 taunt that get 2 attack if you control no another minion also isnt good enough for constructed. The 2/1 statline is also argumenty worse than 1/2 taunt since it dies to hero powers.
I would say it on the border of unplayable/playable since it 2 taunt in one. The most likely deck it will see play in will most likely be in paladin for their quest. if it doesn't make the cut for quest paladin that deck then it has no hope.
The 2 attack on it is horrible since most playable 2 drops have 3 health and so they can attack it 2 times.
I voted Meta defining. This seems like a better sludge belcher for 1 mana less. Will be Like tar creeper. Zoo decks will rin it hecauae its sticky Control will run it because its hard to remove. Thus will see a lot of Play.
This card is good, but people are overrating it, the attack difference in 2/5 vs the 3/5 "belcher" makes this card way more useless in removing minions. Not to mention -1 health overall health than belcher
Maybe it's just me, but I'd rather have Arcane Nullifier X-21 instead of this one. The difference between 2 and 3 attack (to all the people mentioning Sludge Belcher) is huge and a 2/1 is easier to get past than a 1/2.