Whatever the people in the top image are are less iconic than side characters in a 36 year old cartoon. Just that fans of people can't see past 'em. It's nothing new.
When a material changes from a distinct phase to another, it goes through a physical process called phase transition. When gas becomes plasma, it doesn't go through the standard phase transition. Hence plasma-in a general sense-can't be regarded as a distinct phase as solid, liquid and gas phases. It is a phase of the gaseous state. In certain rare cases however, transition from gas to plasma can be described as phase transition.
Plasma by definition is a mixture of free electrons and their ions (possibly negative ions). You need enough energy to liberate electrons from atoms. Roughly speaking, When you put that energy in a solid, energy might be dissipated as heat. If you put that energy in a liqued, energy might be dissipated in vaporization. If you put it in a gas it goes into breaking atoms and molecules (creating plasma). The following figure makes it clearer
They are only ‘iconic’ if you worship and follow trash, simply because other people also follow that trash. If you have a brain, the longest you have seen them in one sitting is the same time it takes you to change the channel.
Sinθ Cosθ Tanθ