Angryverse/Unicron Pig

Something squealing's watching over you

Snorting from the sky above

And there's nothing you can do

Prepare to strike

There'll be no place to run

When you're caught within the hoof

Of the evil Unicorn Pig!

Angry Birds Transformers
Unicron Pig first appeared in the "You've Got the Touch" Challenge Event, commemorating the 30th anniversary of The Transformers: The Movie. He was the primary threat for the whole run of the challenge, though once in a rare while you'd get a "normal" level minus the gigantic floating head. In following Challenge Events, there is a small but significant chance that Unicron Pig can pop up rather than the normal stage, just like Boss Pig. This can be pretty bad for you if you've selected a character not really equipped to handle him, and there really is nothing you can do to predict it!

Unicron Pig stays far in the background, protected by an impenetrable shield (and in the case of the Cobalt Plateaus, the terrain itself, a real pain to work around). After a few seconds he begins to attack, launching salvos of three red-armored, flaming Minion Pigs from his sizable snout, which like the Walking Mortar Tower lava-balls arc through the air and explode on contact. (Luckily these luckless Pigs are worth points even if they explode harmlessly on the ground.) You can throw off his aim with a quick conversion to vehicle mode and back, but he can correct in time for the next salvo. You can tap-target the flaming pigs and destroy them with shots, but since they're in front of Unicron's massive bulk, sometimes you can accidentally target the big guy rather than the immediate threat, so a drag-aim attack tends to work better.

Meanwhile, you have to deal with all the normal stage inconveniences too: block towers crawling with Minion Pigs, falling Monoliths, scrambler missiles et cetera et cetera et cetera... which often means you have to be paying attention to a lot of stuff at once or even the strongest characters can be drained of health very quickly.

Beating Unicron Pig is possible, but you don't have a lot of time to do it. After a bit the shield will flicker and evaporate, leaving Unicron Pig vulnerable to attack. After taking a certain amount of damage (roughly 20% of his maximum health bar), the shield pops up again, and your Event score jumps by 250 points. Approximately twelve seconds after the shield goes up, it will flicker and fade again. The trick is to hit him hard and fast, forcing him to throw up the shield quickly as possible. Bear in mind this won't stop him from launching flaming pigs at you, so you need to be sure to alternate targets as needed. Depleting his health completely before then earns you 1000 points, though sadly he doesn't blow up, just throws up his shield, stops attacking, and floats away on fire, probably to sulk somewhere. Once Astrotrain flies overhead, only a few seconds remain before you lose your chance to beat him. Not long after that point, the shield goes up for good, his health bar vanishes, but thankfully he also stops shooting at you then.

Unicron Pig is affected by Energonicon powers, which can really tip the balance for you (more through luck thanks to his random-encounter-ness). Naturally, some characters are much better suited to handling Unicron Pig than others. Any character with an instant-hit attack like Grimlock Bird or (ironically) Galvatron Pig is a good choice, but anyone with a steady-fire high-speed attack like Bumblebee, Thundercracker, Ricochet or Lockdown can do well. However, faster-moving characters also give you less time to work, since the duration of events are "timed" by distance rather than actual time, yet the duration of his shield is an unwavering twelve-second period no matter what. While you could pre-plan well in the "You've Got the Touch" event, the random-chance nature of his later appearances can screw you up if you happen to have the wrong character in play. Angry Birds Transformers
 * EMP blasts from Electroblast or a shot-down rainbow missile close enough will stun him, so at least he'll stop attacking. But his shield is an automatic defense, so you won't be able to do more than the normal amount of damage before it pops up again.
 * Reflectron can be very effective, as a single hit of reflected-flaming-pig-damage (yes, we just wrote that) can whack of a huge chunk of his health. Not enough to make him throw up the shield on his own, but close! Of course, you take damage from the hit too, so... risky one, that.
 * Powerbot can also be very effective, amplifying the amount of damage you can do in a short time.
 * Shieldor is arguably the most useful Energonicon against the big boss, especially when Monoliths force you to transform and make you lose ground and valuable time to take him out.