It's a bomb-sheep. The Germans would fill up the sheep (both orally and rectally) with the explosive material found in Shambeh Bambehs and steer it to enemy T-34s using highly-trained German Shepherd dogs. This was necessary because the Germans found out that sheep are too dumb to run towards a tank by themselves. When the Russians spotted the sheep, and the dogs running towards them, they would often start cuddling with it and take it to their camp for the wool and the meat (warm clothes and meat were hard to come by on the Eastern Front). When that happened, the bomb would be detonated by remote control.
It is unknown why the sheep wore helmets. But the bayonet was there to give the sheep a last-ditch chance to defend himself if the bomb failed to detonate. Some of the sheep who did that returned to German lines all by themselves, often traveling cross-country. After the war in Germany, these sheep would be lauded as heroes. Not because they failed to detonate the bomb, but because they cut so many throats.
In other words, it's a fluffy, mobile and remote-controlled version of the Shambeh Bambeh. The Germans called it the Schafen Bambeh.