Asskicking Leads to Leadership: There's a reason he's so high up the Space Pirate chain of command.
Contrast that with the unending praise he's had heaped on him since then.
Ascended Extra: In Metroid 1 he was just a one-note mini-boss who guarded one of the lock mechanisms to Mother Brain's hideout.
On his part, he seems to primarily resent her for being the only person to survive his K-2L raid as well as his numerous painful defeats at her hands (many of which required implied-to-be-excruciating cybernetic surgery for him to survive). He personally led the attack on Samus' on Colony K-2L when Samus was a toddler, and killed Samus' mother right in front of her and indirectly killed her father. His clone in Other M learns that Queen Metroids aren't pushovers, either.
Always a Bigger Fish: No matter how tough he gets, Samus will defeat him.
In Super Metroid he takes double damage from Super Missiles.
His breastplate is incomplete and susceptible to powerful strikes or the Grapple Lasso.
His chest is this in his Meta and Omega Ridley forms.
And a lot of the time, if she doesn't have the Plasma Beam, it's the only effective point to attack. However, when Samus wants to really do a number to Ridley, she knows to jam her arm-cannon in his mouth and let loose.