Edmund Clerihew Bentley
Created this form and wrote plenty
To describe folks in verse
With just four lines, quite terse

Carl Sagan
Could talk hours and hours on
Stars, comets and planets,
His knowledge as good as it gets

The Donald,
Far from reticent, but disgruntled,
Out-bluffed all the rest:
He is (not) the person they guessed

The optional prompt from NaPoWriPo 2017 for Day 14 of National Poetry Writing Month/Global Poetry Writing Month is to write a clerihew.
 
Clerihew
~ often silly, were first devised by Edmund Clerihew Bentley
~ the first line is the name of the subject (usually famous)
~ subject is placed in an absurd light, or with unknown or spurious attributes
~ rhyme scheme AABB, and often forced
~ irregular line length and meter