I learnt that giffen good doesn't satisfy the law of demand, but can we draw an offer curve to represent giffen good?
Below is a graph of the price offer curve of good $y$ when income is $48$ units, $p_x = 8$ and the utility function is
U(x,y) = \min\left(2x+2y,x+10\right).
(Based on "Simple Utility Functions with Giffen Demand" by Sørensen).
Good $y$ exhibits Giffen behavior when $0 < p_y < 8$.
A gif of the optimal choice changing as $p_y$ changes is presented below (budget set is grey, indifference curve and optimal bundle are green, income-offer curve is orange dashed line):