Reach Wave 15 on all the Special Ops Survival Maps. For future reference, there are lots of MW3 Title and Emblem Guides online that show all the Titles and Emblems, and explain how to earn them.
unstoppable
The red scope title in MW3 is not the current title used on the game. Currently there is not a way to get that type of title but it may be unlocked in the future.
To get the title 'toxic'in mw3 you must be killed by an enemy MOAB. A MOAB is a giant bomb you get in mw3 for getting a 25 kill streak. Or 24 if you are using the perk Hardline
A title called 'flyswatter'
You Hack
Avenge a fallen teamate
the ~AussiePride~ title you get it buy joining the clan Aus~ on elite
Reach 1st prestige level 65
get 3 finial kill cams in a row
Get 3 kills in one life with your secondary weapon
Win 15 search and destroy matches
Get a game winning killcam with an AC-130