Waddle Dees are a major enemy in the Kirby series, though they often tend to mind their own business rather than actually attacking. However, some actually help Kirby. High up in ranks is a particular Waddle Dee (making him similiar to Toad or Yoshi, in that he is a singular character with a species of look-alikes), and the Waddle Doo.
Instead of being an enemy, Waddle Dees are playable team members in Kirby's Mega Soccer. For unknown reasons, they are banned from scrimmages. Waddle Dees can inhale, as can Kirbys. Their Super Shot is the same as Kirbys, they inhale and blow out the ball. The powerup they obtain from a wand is a hammer that they can use instead of tackling. Also, if a Waddle Dee has a hammer when he uses his Super Shot, he does not inhale and exhale, he hits it with the hammer, identical to King Dedede's Super Shot. They are also optional to pick.
Waddle Dee appears in Mario + Kirby Baseball as a member of Kirby's team. He has amazing pitching and speed, but he has the lowest batting in the game. Yellow Waddle Dee appears as a color change, who has slightly better batting but lower pitching. They appear in the opening playing catch, which teaches Kirby how to play and starts off the chain of events in Dreamland.
Also, Parasol Dee appears on King Dedede's team. He has higher batting, but lower pitching. He uses his parasol as a bat and glove, allowing him greater range when fielding.
In the Pathverse, Waddle Dees serve as the backbone of Devotee City's security and military forces. The Waddle Dees in the Pathverse are armed with basic Spears and Swords and normally are assigned to groups of other Waddle Dees. The Waddle Dee elites are usually signified by Bandanas, more advance spears/swords and partial plating at their shoulders to give them slightly more protection. Waddle Dees also serve other purposes, such as construction working and traveling on trade routes.
Waddle Dee Trainee - Waddle Dees recently enlisted into the Devotee forces, they are normally put into a training session for Waddle Dee Advisors to decide if they should hand out a promotion to the trainees and are never seen on the battlefield.
Waddle Dee Soldier - Basic Waddle Dees which mostly patrol the city and serve as guards at the borders of Devotee City. The Soldiers are normally armed with basic weaponry and don't have a high amount of authority over other Waddle Dees.
Waddle Dee Senior Soldier - Waddle Dees who normally guard the Devotee Castle itself. These Waddle Dees are slightly more heavily armed and can be seen operating some vehicles provided by King Dedede.
Waddle Dee Commander - Waddle Dee Commanders are high ranked Waddle Dees armed with powerful swords and Spears alike, Waddle Dee Commanders can be identified from their shoulder armor and generally command groups of Waddle Dee Soldiers during states of war.
Waddle Dee Advisor - The highest ranked Waddle Dees in Dedede's army. These Waddle Dees command raids on towns affecting Devotee in a negative way and are usually armed with high class weaponry and can be seen wearing Bandanas and Shoulder armor. Waddle Dee Advisors also serve as Dedede's personal guards at Devotee Castle. During the 22nd anniversary of the construction of Devotee Castle, one of Dedede's major advisors is kidnapped by the Blind Man as an effort to escape apocalypse. Dedede becomes paranoid and does a terrible job at being a king because of this, causing economic decline in Devotee City.