Unlike the Samurai and MMPR monsters, these monsters didn't get toys or appeared in major merchandise. They might appeared in books though but I am not sure which ones.
Scaraba
Appeared in Nick.com's Zords of Fury.
Yuffo
Megaforce Episode 2 Monster Yuffo appears in the "Never Surrender" Megaforce game on Nick.com, the 3DS game (above) and the Swappz app game. I think he appeared in a book.
Dragonflay
"Stranger Ranger" Monster appears in the "Never Surrender" Nick.com game.
No Joke
"Last Laugh" Monster appears in the Power Rangers Megaforce Nintendo 3DS game.
Headridge
"Super Megaforce" Episode 1 monster appears in Power Rangers Super Megaforce Nintendo 3DS game Stage One.
Tentacus
Monster from Episode 1 "Super Megaforce" of PRSM appears in level one of the Nick.com PRSM Legacy game.
Cybax
Monster from "Earth Fights Back" of PRSM appears in Level two of the Nick.com PRSM Legacy Game.
Skatana
Monster from "Blue Saber Saga" of PRSM appears in Level 3 of the Nick.com PRSM Legacy Game. He is at Stage 3 of Power Rangers Super Megaforce 3DS game.
Matacore
Monster from "Samurai Surprise" of PRSM appears in Level 4 of the Nick.com PRSM Legacy Game.
Gorgax
Monster from "Silver Lining Part 1" of PRSM appears in Level 5 of Nick.com PRSM Legacy game. He appears at Stage 2 of the Super Megaforce Nintendo 3DS game.
Osegain
Monster from "Silver Lining Part 2" of PRSM appears in Stage 4 of PRSM 3DS game. He is also in Level 6 of Nick.com PRSM Legacy Game.
Skeltox
Monster found in Stage 5 of PRSM 3DS game. My nephew says it is the hardest villain for him to beat.