From the Super Mario Wiki
Elite Pestnuts are small, round, urchin-like enemies that appear in Mario & Luigi: Superstar Saga and the remake, Mario & Luigi: Superstar Saga + Bowser's Minions. They are the stronger variety of Pestnuts, and only appear in battle alongside Bloopers on the Oho Ocean Seabed. The original game simply called them Pestnuts like their base counterparts; the remake of the game gives them their current name.
Elite Pestnuts are covered in spikes like regular Pestnuts, making them impossible to jump on, unless Mario or Luigi wear any of the "Spiny-Killer Jump" Badges. They share the same attack pattern as well, with two rolling attacks that much each be dodged with a jump or countered with a hammer; the attacks come faster and deal more damage in addition to possibly poisoning the Mario Bros. on contact.
After the Elite Pestnut takes enough damage, the outer shell breaks, revealing a Beanie or Gold Beanie underneath. However, once this happens they will float up to the surface; in the 3DS remake, they will drown instead. In both cases, this counts as defeating the foe and still gives out Experience Points, coins, and item drops.
Elite Pestnuts also appear as enemies in Minion Quest: The Search for Bowser. They are melee troopers, and attack by rolling into their opponents. Their special skill is Spin to Win, allowing them to roll into a minion three times. Due to their spikes, attacking a Pestnut from the side or from above cause damage to the minion. Elite Pestnuts are weak against Spear Guys.
Profiles and statistics
Mario & Luigi: Superstar Saga / Mario & Luigi: Superstar Saga + Bowser's Minions
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