Propeller

Propeller (originally Propeller Bomb in Kirby's Dream Land 2) is an enemy in the Kirby franchise, making its debut in Kirby's Dream Land 2. Originally, it grants no copy ability, but in Kirby 64: The Crystal Shards, it yields Ice, which is the only exception thus far in the entire series that it grants a copy ability at all.

Physical appearance
Propeller is a droplet-like creature with 2 propellers (hence the name itself, but in its debut, it only had a singular propeller). Throughout the series, Propeller has been portrayed with different colors such as red, green (only seen in its artwork in Kirby's Dream Land 2), red, orange, grey and blue (a generally common color throughout the series).

Kirby's Dream Land 2
When Kirby approaches it with an Animal Friend, it puts on an angry glare and starts chasing the player around. If it touches an animal friend Kirby is riding on, that partner will quickly flee in the form of a star, and Propeller will change back into its docile form. There is a way to defeat it when you are with your animal partner: Freezing it with your Ice ability, which is apparently its weakness if you have said partner with you. However, after a short time, it may explode or go off-screen.

Kirby's Dream Land 3
Propeller appears again, but this time, hatching from Propeller eggs in order to chase the player with an Animal Friend. The only Animal Friend that it has no effect on is Pitch, and will not react to him.

Kirby 64: The Crystal Shards
Propeller appears once again as an enemy as usual. However, the only difference this time is that it yields the Ice ability when inhaled.