Wonder Thwack

The Wonder Thwack is the most powerful variety of Thwack. They resided at the Star Shrine during the events of Mario & Luigi: Partners in Time. Like regular Thwacks, they come in two colors: red and blue. However, unlike Thwacks, Wonder Thwacks are always glowing.

In battle, Wonder Thwacks use the same attacks as regular Thwacks, but they move a lot faster when attacking. Before each attack, a Wonder Thwack will twirl and either remain the same color or switch to a different color. If red, it will attack Mario; if blue, the block monster will attack Luigi. After twirling, the Wonder Thwack will attempt to crush the appropriate Mario brother. However, since they fly higher than normal Thwacks, the Baby Mario Bros. must wait until the Wonder Thwack drops within range before countering with their Hammers. Regular Thwacks can be attacked when hovering, instead of falling.

Wonder Thwacks can also fly low and ram into a Mario brother. The heroic brothers can dodge or counter this attack by jumping. Additionally, like their weaker counterparts, they can summon more of their kind to join the battle. Wonder Thwacks may also turn yellow after twirling and attempt a last ditch suicide attack. After turning yellow, they will split into two yellow boulders. Each boulder will roll towards a Mario brother. Mario and Luigi could dodge this attack by jumping, but they had to be quick. Red Wonder Thwacks are resilient to Bro Flowers and Mix Flowers, while blue ones are resilient to Ice Flowers. Each color will receive more damage from items that its counterpart is strong against.

Unlike the Thwacks, the Wonder Thwacks do not group to form a Thwack Totem themselves.

Even though they are more powerful than normal Thwacks, Wonder Thwacks still have the same amount of HP.