Tough Waddle Dee has the same basic appearance as a standard Waddle Dee. However, unlike basic Waddle Dees, the Tough Waddle Dee has metallic silver skin covering its entire body except for its face, which remains beige. It is also completely immobile, staying firmly anchored in one spot. The only exception to this rule is when it takes damage. Other than that, Tough Waddle Dee will idly swing its hands back and forth.
The Tough Waddle Dee is unique from normal Waddle Dees in that it is both completely invincible and immobile. It simply stands, unmoving, in the lower room of the Copy Ability Testing Room until Kirby begins attacking it. Even the most powerful of Kirby's Copy Abilities are incapable of even dealing minor damage to it. As it is meant to act as a dummy for Kirby to test his Copy Abilities on, the Tough Waddle Dee is also immune to Kirby's Inhale.
The Tough Waddle Dee is also unique in that it does not deal any damage to Kirby in the event Kirby collides with it. However, colliding with the Tough Waddle Dee will still cause Kirby to be knocked back and gain invincibility frames, as if he had taken damage.
In Kirby: Planet Robobot, Tough Waddle Dee appears in the Ability Testing Area. It behaves like it does in Kirby: Triple Deluxe.
- It is possible to move Tough Waddle Dee from the central area in Kirby: Planet Robobot's Ability Testing Area. By using Jet's Hover technique above the enemy with careful timing, Kirby can lift it into the air and knock it out of the box.
- As Tough Waddle Dee is invincible, some moves that would normally be an automatic KO are ineffective when used against it, such as being frozen by Kirby's Ice ability.
- Just as Tough Waddle Dee cannot be Inhaled, it cannot be captured with the UFO ability.
- Tough Waddle Dee serves the same purpose as the training dummies found in the Lor Starcutter's Copy Ability rooms in Kirby's Return to Dream Land and the training rooms in Kirby's Dream Collection: Special Edition. Unlike the training dummies, Tough Waddle Dee cannot be defeated.