According to the dialog in the end of each one of the Cogs capable of reaching level 12 can also reach level 50.
The only known cases of level 50 Cogs are the following:
- The Director of Ambush Marketing, which is a level 50 Skelecog.
- Toons who have maxed their Cog Disguise, and reached level 50.
- Oddly, the bosses that have HP only have about 500 HP, which would rank them far below level 50 (which, according to the HP formula, should be level 20.866 Cogs).