Understanding EOS SUBCKT behavior
It is a voltage dependent input offset source


  The offset voltage-source, Eos, provides a supply voltage dependent
  input offset voltage and reflects the error voltages from the power
  supply rejection ratio stage, the thermal effect stage, and the
  noise-voltage source. Below is a diagram of the Eos polynomial-source
  and the effects that correspond to each term.




From: AN-840 Development of an Extensive SPICE Macromodel for "Current Feedback" Amplifiers