The creators of Family Guy probably didn't invest too much money and effort into small pieces of background props like these. Therefore, I'd assume that they didn't use any actual characters, for which they would have needed to pay licensing fees, negotiate how the characters may and may be not be used and so forth.
I'd assume they rather drew up some "superhero-y" figures who have the typical attributes many "real" superheros have. The first one seems to pick up the "bird prototype" like for example Hawk Man or the Winged Bird-Men from Flash Gordon.
The second one goes for the "animalistic/force of nature plus muscles, and more muscles" variant, like Beast (especially how he looked in the 90s), Hulk or Thing. The third one is probably a Silver Surfer with a different color scheme. The one you connected to Triton might also have a bit of Swamp Thing in its line of ancestors.
So, they're probably no actual characters, but generic figures that transport the idea "Chris is into superheroes".