Translation:That mosquito is mine, not theirs.
We're talking about a special mutant mosquito that grants a superpower to the one it bites: being extremely annoying.
Really weird sentence, can it be a domesticated animal so it makes sense?
Sentences like these challenge our vocab knowledge. Yeah it's complete nonsense, but hey, you understood what it says right? =)
I guess this person keeps one single mosquito as a pet? Considering their lifespan, doesn't really happen in reality.