World will not render, chunks repeat, old snapshot worlds and current snapshot worlds, unidentified object (pink, large, gear-like texture in (?) middle

When I spawn, one chunk will repeat itself and it will flash through chunks, also, about 10 blocks away (from my spawn) is a large pink object with patches of grey (in a cog shape?), which will try to render, carpet-like. less detailed, about 20 times bigger. It has no depth, but changed with user's perspective. This occurs on multiple worlds. There is a second one, a white striped one. They move as if mobs? They will swivel.
EDITED: THE THINGS ARE PIGS AND CHICKENS I REPEAT THEY ARE PIGS AND CHICKENS.