Banana Bomb:
Complete Shotgun Challenge 3. 

Mad Cows:
Complete Shotgun Challenge 3 with all golds. 

Nuclear Bomb:
Complete Deathmatch Challenge 10 with all golds.

Bridge Kit:
In the Beefcake Breakfast, get the crate located on a 
rooftop. 

Earthquake Weapon:
Complete Jetpack Challenge 3. 

Super Sheep:
Complete Sheep Challenge 3