First of all Croocodile is the first Logia-user that Luffy defeated.
Miss Goldenweek’s Rainbow Color Trap reveals that his dream was to become the Pirate King.
The soundtrack playing during Crocodile’s defeat is Dvorak’s New World Symphony, specifically the 4th movement, “Allegro con fuoco”. It was the third time in the anime when a piece of classical music was played in the anime (The first being Buggy and Gaimon’s farewell, during which Chopin’s Etude in E Major played, the second beingDr. Hiluluk’s last speech, during which Ave Maria was played and the fourth being when the zombies claimed Absalom as their leader, with Ludwig van Beethoven’s rendition of Ode to Joy).
It was noted that if the World Government had known Crocodile was head of Baroque Works, his bounty would be at least 162,000,000.
Crocodile is the first Shichibukai to be defeated by Luffy.
Crocodile is the only one of the original Shichibukai to possess a Logia Devil Fruit.
Crocodile shares some similarities with Doflamingo:
They are both former Shichibukai.
They both are/were leaders of a powerful criminal organization with several Devil Fruit users.
Crocodile was the main antagonist of the second saga of Part 1 (Baroque Works Saga), while Doflamingo was the main antagonist of the second saga of Part 2 (Pirate Alliance Saga).
They both are Devil Fruit users and have mastered their powers to high levels and both are aware that Devil Fruit powers can be awakened (in fact Crocodile was the first character to mention the concept of a Devil Fruit being awakened when he explained the Jailer Beastswhere Awakened Zoan Devil Fruit users while Doflamingo is the first Awakened ParameciaDevil Fruit user to be shown).
They both use coats as their common clothes.
They both were present at Roger’s execution.
They both aimed to control a whole country (with Doflamingo having succeeded).
They both contrabanded illegal sustances (Dance Powder and SAD).
Both characters’ defeats at the hands of Monkey D. Luffy seem to mirror each other:
Luffy defeated Crocodile by blasting through Crocodile’s single attack with a barrage of punches, launching him through an underground cavern and into the air.
Luffy defeated Doflamingo by countering a large group of Doflamingo’s attacks with one powerful punch, launching him through the air and into an underground cavern.
In the 5th Japanese Fan Poll, Crocodile is ranked the 15th most popular character in One Piece, making him the 2nd most popular of the original Shichibukai, the 3rd overall, and the most popular antagonist in the series. Coincidentally, 15 is the same spot he occupied in the first poll he was in.