Puffer-Cheep

Puffer-Cheeps are indigo varieties of Cheep Cheeps that appear in Mario & Luigi: Superstar Saga. They are found on the Seabed. The Nintendo Power guide refers to the Sand Cheep as a "Puffer-Cheep" or Puffer Cheep, while the actual Puffer-Cheep is referred to as a "Puffy Cheep".

In Mario & Luigi: Superstar Saga + Bowser's Minions, they and their base form are replaced by Spiny Cheep Cheeps, which similarly toggle between standard and spiny.

Battle
Cheep Cheeps attack at first by ramming into Mario or Luigi, who have to jump to avoid or counter it; if damaged, the Cheep Cheep puffs itself up, transforming into a Puffer-Cheep and revealing spines that prevent the Mario Bros. from jumping on it. In this form, it will attempt to ram into the Mario Bros. again, which must be countered with the hammer this time; the Bros. will be poisoned if the attack hits or if they attempt to jump on it without the proper badge. If the Puffer-Cheep is damaged again, it reverts back to its original Cheep Cheep form; if it is jumped on without the proper badge or hits one of the brothers, they may become poisoned.