At least those three faces
can't be stacked:
For anyone who doesn't know WTF is going on: Yes, Dota 2 screenshot. What's going on here is that Dire's creeps (Red minions) are being intentionally held back by the Ice Shards (a spell that Tusk - Dota 2's local walrus bar brawler with a couple of his spells being Walrus PUNCH and Walrus Kick has). One of Tusk's late game talents is a major cooldown buff to Ice Shards, which is what stalls successive waves of creeps and allows this army to eventually form.
Oh and these are Mega Creeps, basically the equal to Super Minions in LoL but permanent.
By the way, the giant snake? A tower.
Suck stacking / stalling tactics have been used every now and then, and the opponent team has the best counter to this - another player is playing Earthshaker. Not only does Earthshaker's Fissure do similar things as Ice Shards, his Ultimate - Echo Slam - deals damage based on the number of units in the vicinity. Had the Earthshaker player held onto his Ultimate he could've one shot both the army and any unfortunate players.
(I dunno how to feel about the fact that the explanation wound up this long.)