Here's a link to a good online name generator. If you're going to be a writer, you need to learn how to invent names.
clawdia
The Monster Slam The Good Bye The Twisted Neck The Knocker
Players on Moshi Monsters give their Moshi Monster a name when they first adopt it. Most monsters are only given one name and do not have a "last name". However, you could consider their last name to be the name of their monster species or type. So the monster's last names would be Luvli, Furi, Katsuma, Poppet, Zommer, or Diavlo.
Elmo's last name is Monster, they(the people that make Sesame Street) have mentioned this numerous times throughout the series. Many of the monsters last names are Monster.
Purrsephone doesn't have a last name, her name is just Purrsephonie.
Here's a good link listing the top 1,000 American last names!
ifrit,pyro,cyndaquil, roy mustang (lol)
If you are looking for American graphic novels, you can try the Walking Dead, Watchmen, Y: The Last Man, and Batman: The Killing Joke. Some good foreign graphic novels are Akira, Monster, Sanctuary, and Persepolis.
cordoba
Beaverhausen
Any Korean last names. Such as; Kim, Song, Lee, Choi, Yim, etc.
Whatever name you like is a good one -- you're the writer! Here's a link to show how authors pick good names.