War with the monster

Annabeth and I had decided to go for a nice long walk on the beach and we 'accidentally' cross the camp borders, it was just a normal stroll down the beach and we were starting to walk back to the cabins. "Why are you so concerned that we should stay in camp borders, I mean come on we are eighteen now we can wander around more and anyways I have you to protect me" Annabeth said.
"I know but don't you think that since we're older we are easily found and attacked." I argued.
"And why would our age have anything to do with it?" She told me.
"Because we are older and more dangerous to the monsters of the world Annabeth...." I said and then all of a sudden, we heard it, the beast.

Notes

Hey guys, I'm sorry if you don't like it but I couldn't think of a monster for the story so I had to cut it short and also this is my first fanfiction. So I'm open for suggestions on the monster. Just comment below a monster and I'll try to pick the top five and let you guys vote on what it should be. I'll update once I have a monster to put in the story. See ya.