Many reptilian pets, including large ones make great pets. I have fifteen reptiles, five of them being snakes. Only one will get over 6 foot. I have owned a 9 1/2 foot boa constrictor. She was also sweet. She only bit me once, which was my fault. I reached in, touched her, she startled ad recoiled, so I pulled back and then went back in and she struck me. I have had large monitors before. I have a savannah monitor now. I want a white throat monitor.
Some reptiles, like your GIF above and your aforementioned Nile monitor, just have bad attitudes and to find one with a good one is hard to do. The white throat and its larger relative the black throat tend to lean more like puppy dog tame. Some pythons and boas just have mean attitudes, but most are docile. Bearded dragons are wonderful medium-sized lizards that seem to enjoy human interaction.
I also have nine tarantulas. These are more look but do not touch. I could handle one or two if I wanted to as they are docile as far as tarantulas go.