There are two of them in the forest area in the Story Mode. One of them is an orange Spear Guy(or girl) named Hula. To get her gadget, you follow her dance moves by moving left (A), moving right (B), or spinning (↑↓← →). You will also see her in the credits at the end of the game after getting all the gadgets. You dance however you like.
The second one is a red Spear Guy that you must face in a duel in order if you want to keep his duel game. You must have a mustache in order to face him, which means that you have to play as Mario or Luigi.
Spear Guys appear in two ways: as a throwable orb and a King of the River mode enemy. As an orb, once it is set, an opponent that lands on it will be sprung into a tree. There, the spear guy will ask them to roll a dice block which determines how many coins they give to the owner of the orb (5, 10, 20, or 30). The spear guy then spears them. As an opponent in the King of the River game, they will show as your challengers, and you must accept the mini-game they challenge you to or quit the game. If you fail the game, they will throw the spear at your boat and damage it.
Spear Guys made an appearance in the stage, DK's Treetop Temple. When a player lands their space, a Spear Guy appears and will steal a piece of candy. However, they will give coins in return.
Super Mario World 2: Yoshi's Island/Yoshi's Island DS
They were first found in Yoshi's Island. In Yoshi's Island DS, They are seen holding the spear sideways, or straight up in the air trying to hurt Yoshi, in jungle levels of Yoshi's Island DS, some are seen dancing around platforms.
Spear Guys are only seen on Lavalava Island in Jade Jungle. In this game, Spear Guys can throw their spears at Mario causing damage. They can also point their spears upward or forward. If they point their spears upward, Mario must hammer the Spear Guy. If the Spear Guy points their spear forward, Mario must then jump on them (because if he uses the hammer, he'll run right into the spear causing damage.
Showing up as common enemies, Spear Guys cause lots of trouble for Mario. In addition to ambushing and attacking Mario, three Spear Guys steal pieces of the bridge to stop Mario from proceeding further. Later, they throw their spears at Mario as he rides on a raft.
Spear Guys are only seen as supporting enemies of the giant fight with Dreamy Bowser in this game. They come in many groups and they attack Dreamy Luigi by poking their spears at him slowing knocking down his HP. Dreamy Luigi must shake them off before they cause too much damage. As the battle progresses, another group of Spear Guys will come out meaning Dreamy Luigi must now shake off two groups of Spear Guys.
Spear Guys appear in paper form in this game where they are fought in Gloomy Woods. In battle, Spear Guys can use a variety of attacks depending on the number stack they have. One of their main attacks involves throwing their spears where only one of the spears will hit either Mario, Luigi, or Paper Mario which must be hammered away. Another attack involves the Spear Guys surrounding the heroes and then throwing their spears at them which must be evaded with a jump.