SpongeBob 

Or

Marvin The Martian 

Marvin The Martian

Author: My money is on marvin cause SpongeBob can't really survive a Laser sense he's still a sponge and,sense marvin is an Alien he probably One shot SpongeBob by just well Shooting A Giant Laser at spongebob and Bam Dead now if Marvin is in Spongebobs world then Spongebobs cartoon powers will give him an advantage and depending the episode marvin is in like the one with Spongebob getting a magic pencil well spongebob could beable to erase MArvin from existance but if Marvin is his normal size then Spongebob is still Fucked and,Dead So Yeah Marvin wins in my opinion