Are Sci-Fi original movies like Mega Man? They all end in -Man.
No.
Sometimes they end in Monster. Like Swamp Monster and Rock Monster.
Sometimes they just take a word and put it next to Alien. Examples include: Alien Invasion, Alien Express (aliens invade a train), and Alien Incursion (Whatever that is)
Sometimes they like to use a single word explaining the animal. Such as Kaw (For killer crows), Locust, Mosquito, or The Hive (Which was about Ants... not bees *Slaps forehead*)
Sometimes they'll be named after the animal in question: Pterodactyl, Sabertooth, Rottweiler.
And many times they'll just have such silly names that it amazes me they had the balls to display their names in the credits. Aztec Rex (T-rex vs Cortez vs Aztecs), Killer Bird Flu (About giant birds that eat people... and also have bird flu for some reason), Boa vs Python (It's about what you think it's about), SS Doomtrooper (Nazi super soldier), Frankenfish (Again... it's about what you think it's about), and the list goes on.
If you're really into bad movies (beyond SciFi too) I have a list I wrote up giving out awards for subpar performances in various areas such as: Most stereotypical characters, Most shallow plot, Stiffest action scenes, worst CGI, most unnecessary explosion, and so on. We call them the Crummies.