A lot of people say that of the 3 original Nicktoons, Ren & Stimpy were the odd one out on virtue of being edgier than the cutesy slice-of-life toons that acompanied it. I understand where they're coming from, but honestly I see it as Rugrats being the middle ground between Doug and Ren & Stimpy - a cute slice of life show with relatable kid protagonists like Doug, but one that like R&S wasn't afraid to delve into unsettling imagery or gross-out humour. Though those latter similarities did get neutered once the show got uncancelled, and it never went as extreme as R&S in the first place, so I can still see why people think of R&S as the odd one out.