Topmaniac

Topmaniac is a boss in the game Super Mario Galaxy. He resembles a red spinning top, and is the leader of the Topman tribe. He is fought up to four times when Prankster Comets are taken into account; twice in the Battlerock Galaxy and twice in the Dreadnought Galaxy, making him the most fought boss in the game. His name is a combination of Topman, his species, and maniac, possibly referring to his buzz saw and aggressive behaviour.

Appearance
Topmaniac is simply a larger Topman. Most Topmen have spikes on their tops, but Topmaniac has ten yellow spikes on his side and a flat, red top. He attacks Mario by spinning into him with its spikes and occasionally by jumping into him after being hurt. He also has two robotic-looking yellow eyes on his front along with a couple green arrows pointing in the direction of its rotation.

Battlerock Galaxy
Topmaniac is fought for the first time in the Battlerock Galaxy, in the level, Topmaniac and the Topman Tribe at the very end on the Topman Planet.

In this battle, Mario must hit Topmaniac three times, each time getting harder, to finally knock it out and win the battle. This format is seen in many of the Super Mario Galaxy bosses. The location of the battle is an arena with electric barriers on the side for Mario to hit if he gets blasted off to the side. At the beginning of the battle, Topmaniac will fall from the sky with 3 Topminis, and try to either hit Mario with its spikes or get the Topminis to ram him into a wall.

To hit Topmaniac, Mario must jump on top of him, which will force it to retract its spikes and spin closer to the walls, Mario must then Spin into it, knocking him into the wall, making him lose one life. Mario must repeat this three times to win. However, if Mario defeats the enemies he summons, Topmaniac will go for Mario instead of just spinning around randomly. On the third time, instead of Topminis, Topmaniac will use Spiky Topmen, who also attack Mario. After Topmaniac is defeated, he releases his Power Star and the level is completed.

Topmaniac is fought again in this galaxy when a Daredevil Comet comes, which forces Mario to defeat him with only one health.

Dreadnought Galaxy
In the Dreadnought Galaxy, Topmaniac is battled again. This time the level is called Revenge of the Topman Tribe, and he is fought in a different location. In this location there are, once again, electric barriers, but this time they are moving.

In battle, Topmaniac must be hit three times once again, and has the basic same strategy as the time before with one minor difference: in this battle, Topmaniac begins with two Spiky Topmen instead of Topminis as before.

Once again, Topmaniac is battled when a Prankster Comet arrives. However, this time, the comet is the Speedy Comet, which forces Mario to defeat him within a set time limit.

Trivia

 * Topmaniac shares the same boss music as King Kaliente and Bugaboom.
 * It seems that during production of Super Mario Galaxy, Topmaniac was originally going to be fought in the Melty Molten Galaxy, which had several elements from the Dreadnought Galaxy. Here, it was actually gray with light gray stripes, instead of blue arrows. Its head was rounded at the top like a normal Topman (instead of the big red light) and its head would rise up like one too.
 * Although all other species of Topmen appear in Super Mario Galaxy 2, Topmaniac is absent from the game.