Interlac

"As the official U.P. language, Interlac is taught in schools throughout the system and is the common form of communication between most sentient United Planet races."  - Who's Who in the Legion of Super-Heroes #   1

Interlac is a DC Comics fictional language. It is the main language used by 30th century United Planets (think the United Nations IN SPACE) in the Legion of Super Heroes comics. It was first referenced in Adventure Comics # 379.  However, the actual letters and numbers weren't reveal until years in Legion of Super-Heroes (Volume 2) # 312 by writer Paul Levitz and artist Keith Giffen. 
Language / Numbering System
The language has 26 letters that corresponds with each the English letters and it's numbering system uses a ten as a base (as shown above). As such, it has ten digits corresponding with 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0. However, the numbering system is flawed due to 42 and 7 looking the same. It has a similar problem with 41 and 6. Despite being written differently, Interlac sounds exactly like English.
Babylon 5
In Babylon 5, there is an unrelated language also called Interlac. This version of Interlac is a universal language based on math. This is flawed idea to the possibility of aliens having non-decimal based numbering system.
Reference:
http://en.wikipedia.org/wiki/Interlac

Mercury Man

Mercury Man was a Golden Age superhero who has fallen under public domain. So, now anyone can use him without approval from his original publisher.
Merco was an alien from the planet Mercury. They were "ruled by greed, hatred, and fear". Since they have super advanced weapons, they ended up killing each other in nuclear Armageddon. However, Merco managed survived because the radiation gave him super powers and turned him metallic... for some reason. He had small wings on his ankle and had wing-like ears. He went to Earth as the superhero Mercury Man to prevent the Earth from suffering the same fate. He stopped a nuclear attack on the US. Dr. Penn (a female scientist he met) gave him the power to become a normal human and turn back (although his metallic form was the only time he could use his powers). The next time we see him, he (now in a different costume) takes various "warmongers" to Mercury to show what could happen to Earth if they don't change their ways and trap them there when they refuse to do so.
Merucry Man has a variety of powers. He can fly, turn into mercury, fire disintegration bolts, use minor telepathy (which allows him to find people) and has super strength. He has also been shown surviving in the vacuum of space and the explosion of a nuclear bomb. He also has scientist-level intelligence.
My sources were:

• http://pdsh.wikia.com/wiki/Mercury_Man
• http://en.wikipedia.org/wiki/Mercury_Man
• http://www.comicvine.com/mercury-man/29-71497/

Grasshopper

Neil Shelton

The Grasshopper(s) is a series of parody superheroes of the same name that each die shortly after they are introduced to spoof the tendency of superheroes dying and being replaced by a new hero with the same name. My main source was Wikipedia.

Doug Taggert
He was an employee for Roxxon Oil (an fictional oil company). He was a security guard that used a suit of power armor allowing him to jump superhuman heights, but provides little to no protection despite being armor. Doug has a crush on  his co-worker Cindy Shelton, who has a crush on the Grasshopper (his alter ego). He tried to stop a robbery and joined the Great Lake Avengers... for five seconds, since the Batroc's Brigade (the people committing the robbery) killed him shortly after.
Neil Shelton
Neil was another Roxxon security guard that gained Doug's suit. However, it was altered and was more like Iron Man's. Cindy Shelton fell in love with him thinking he was the original Grasshopper. Unfortunately, she was Neil's cousin. So, Neil used his "Maximum Jump" to avoid her, which (according to Doorman) killed him because he exited the Earth's atmosphere and burned upon reentry into the Earth's atmosphere.
Unknown
A person claiming to be "The All-New Grasshopper" was a member of the GLA (now called the "Great Lakes Initiative"). His neck was snapped by a disgruntled Deadpool when the latter was kicked off the team.
Skrull Impostor
A fourth Grasshopper joined the team. He was revealed to be a Skrull (a type of shape shifting alien) impostor. Mr. Immortal (the team leader) was shocked while Big Bertha (a female member of the GLA) thought it was obvious.
References:

• http://en.wikipedia.org/wiki/Grasshopper_(comics)