Steam characters [duplicate]

During big sales or special deals, Steam changes its background images to those containing their own characters:

enter image description hereenter image description here Who are these guys? What are their names? How can we be friends?


Solution 1:

Tappet

Tappet
Tappet is the orange Steam mascot with adjustable antenna horns.

Cyl

Cyl
Cyl is the cynical, mischievous, dark mascot.

Sir Roderick Bodkin

Sir Roderick Bodkin
Sir Roderick Bodkin is the happy yellow hazmat suit mascot.


The other three appear less often, and I can't find any information on their names.