This is the list of bosses, and their details and attacks, that appear in Smash Bros. Lawl. Please note that these are the attacks shown only in the footage.
Major Bosses in the Subspace Emissary
His attack pattern involves swiping his claws at the player and roaring to summon boulders from the ceiling.
To defeat him, the player must dodge his attacks and grab the last rock of the boulder avalanche. Then he must toss the rock into Glutko's mouth. Glutko will choke on it and make himself vulnerable to attacks.
His attack pattern is random. When he has his ghostly tail, he performs an attack by snapping his fingers. One attack involves creating explosions near the player. Another attack involves spawning a giant snake that dashes towards the opponent twice, then falls on him/her. When his ghostly tail disappears, the genie will try to wallop the player.
The only way to hurt him is to attack the game cartridge he was summoned from when his tail disappears while avoiding his walloping. Once he takes enough hits, the cartridge explodes and the Game Genie disappears.
Scratch and Grounder
The robots in Sparta have unusual attacks. Scratch flies in the air, dropping egg bombs, while Grounder attacks by swinging hammers, throwing pumpkins, and stretching his hand out at the player. They may even drive a tall tank coming from off-screen and fire four bombs at the player.
Scratch has his own attack pattern in Final Forest. In addition to dropping egg bombs, he swoops, drops blue armadillo robots that roll into the player, and fires from his... crotch cannon. This battle also has a two-minute time limit.
Grounder can only be damaged by shoving the egg bombs at the numbskull. Scratch can be hurt by attacking the armadillo robots and then sending them flying towards the feathered fiend. Both explode upon their defeats.
Big Red will stretch its neck to swallow the player, which results in an instant KO. If unsuccessful, it will roar and summon a hand that knocks the player closer to the creature's mouth. It will even descend from the ceiling to chomp on the player.
The boss is only vulnerable to any attack if the player dupes it to close its mouth around Kyukyu-Kun.
The Persian Messenger is a major member of the Persian Army who is famous for being kicked into the pit by Leonidas in 300. However, when he encounters Leonidas in the Persian Forest, he enacts revenge.
This boss has the most formidable attack pattern of all the bosses. He is always zipping across the screen with his horse, doing massive damage to the unsuspecting player. Sometimes, he may fool the player by zipping in front of the battlefield. He'll summon a Persian Archer with a flaming arrow to fire at the player off-screen, summon three Persian Soldiers, or throw bombs, all while bantering "This is madness!" or other quotes.
Defeating this boss is tricky. The player must dupe the Archer to fire his arrows at the rod at the center of the screen. When the Persian Messenger does his rush attack, he stops and his horse whinnies before turning to the other direction, giving the player only a few seconds to hurt him.
Chuck Norris is a famous movie star and internet meme, and the final boss of Classic Mode. His attack pattern is unknown. When the player defeats him, he gives him/her a thumbs up.