Marvel Heroes Omega

While the Steam description is lacking in details, you can access the in-game achievement menu (by pressing 'v') to get all the info you need. But, for clarity's sake, there are three 'special' items you must pick up in-game to unlock this achievement. They are:

-Bacon-Wrapped Hot Dog
-Ryolnir's Beard
-The Doomsaw

All three can be acquired as daily log-in gifts; The Bacon-Wrapped Hot Dog on Day 33, Ryolnir's Beard on Day 66, and The Doomsaw on Day 99.

They can also be obtained as rewards for completing other in-game achievements.

The Bacon-Wrapped Hot Dog is rewarded for completing the 'Crispy Bacon' achievement, which requires you to beat the boss character Pyro 20 times, while playing as the Human Torch, with Spider-Ham as your pet.

Ryolnir's Beard is rewarded for completing the 'Fear the Beard' achievement, which requires you to defeat 'Brother Ryolnir' (an elite mob that spawns in the 'Mine Shaft' treasure room in Chapter 8) 20 times.

The Doomsaw is rewarded for completing the 'All in Doom's Time' achievement, which requires you to access the Cosmic Terminal for Doctor Doom, and defeat him within 60 of entering his throne room in a solo run.

The Doomsaw can also be obtained by completing the 'Thanks, Gaz!' achievement, which requires you to defeat all of the in-game incarnations of the Gazillon staff, who are all represented in-game as enemies. The in-game list has 24 enemies.