Is it possible to classify Hopf algebras $H$, over a field $k$, which admit a unique (up to isomorphism) irreducible comodule, namely the trivial $1$-dim comodule $$ k \to k \otimes H, ~~ v \mapsto v \otimes 1_H. $$$$ k \to k \otimes H, ~~ k \mapsto k \otimes 1_H. $$