Downzor
Downzor theroy is that if people with down syndrome interbreed too much they well create a new geneticly subhuman race of people called Downzors
Downzors live off Big Macs and milkshakes, they have super low chins and massive heads, they also have hightend dribble glands and as defence the can use a spray of spit to get away. 
the Downzors have low intelligence  

a downzor mother can have 5 babies at a time but she dies in child birth because they burst out her chest. 
"Dude look at them two downys get it on, if we dont stop it they could make a right Downzor kids"

"RUN! the downzors are coming from the hills, give them Big Macs for i lives"