Like the monsters back in the day of Mighty Morphin Power Rangers, the monsters of Power Rangers Samurai appear in merchandise. Here I catalog which ones, let me know which ones I missed---like always, right?!
Scorpionic appears in the Wii/DSi game and the Nick.com game.
Roofer appears on Nick.com, Wii/DSi game, Squinkies and Samurai Samsh iPhone game.
Negatron appears in Samurai Smash app and Squinkies figure.
Robtish appears in the Wii/DSi game, the Nick.com game, other media.
Madimot has a Squinkies figure.
Desparino has a Squinkies figure. He also has an Action Card Game (ACG) card.
Vulpes appears in the Nick.com game and other media.
Steelo has a Squinkies figure. He also has an Action Card Game (ACG) card.
Antberry has a Squinkies figure.
Arachnitor appears in the Wii/DSi game, and the Nick.com game.
Duplicator has his Japanese name Dokurobou in the Nick.com game.
Fiera was given her Japanese name Yomotsugari in the Nick.com game. She is probably there because she is the only female monster.
Armadeevil has his original Japanese name Marigomori on the Nick.com game.
Squinkies, thanks to PRS facebook page:
Antberry, Desparino, Negatron and Yamiror.
?? (Nakinakite? Xandred?) and Madimot
Steelo, Tooyain, Deker, Dayu, Octoroo, and Rofer