BOB-1 & BOB-2 are a miniboss from Contra III: The Alien Wars in level 3 Neo Kobe Steel Factory right before Big Fuzz. They are Red and Blue robots who hop around and attack the player(s) with gunfire and tackles. They also can hang from the ceiling. After taking enough hits, their lower body busts off but the upper body scurries and jumps around until it takes enough damage and blows. The best way to beat em is to stay on the wall and ceiling and keep firing.
Like Big Fuzz they seem to be modeled after the robot from the 1st Terminator film, especially with how they keep going after getting their legs taken out.