Bubbles

The Bubbles (ハリセンボ) is a pufferfish-type Badnik model that is created by Dr. Eggman. It makes its debut at Marble Garden Zone in Sonic the Hedgehog 3. Bubbles are seen hovering around lonely or on groups and after seeing its target, they start quickly reveal their spikes out their body in order to wound the player.

Sonic the Hedgehog 3
Bubbles are first seen inhabiting Marble Garden Zone, which is located on the Floating Island in Sonic the Hedgehog 3. Like Spiker (which are also inhabiting Marble Garden Zone as well), it is very deceiving in appearance with its smooth, spherical blue body and nozzle-shaped head.

Bubbles are seen hovering around Marble Garden Zone lonely before the player's approaching. When the player is close to the Bubbles, it starts hovering toward him and starts revealing spikes from its body and then hide then back to its body. It can be destroyed when its spikes are retracted by performing Spin Jump toward Bubbles, and with the correct timing, its thorny defense can be successfully penetrated with Sonic's Insta-Shield. However the player has to be careful, while timing his / her jumping ability or the Insta-Shield, because with wrong timing, Bubbles will reveal its spikes at the same time and can possibly hurt the player, who will lose shield, rings or even life during that time.

Sonic the Hedgehog 4
Bubbles makes a returning appearance as common enemies in both episodes of Sonic the Hedgehog 4. This time it appears in two colors. The traditional blue Bubbles with spikes is present; however, due to Eggman's budget cuts, these Bubbles don't have any spikes. Red Bubbles make their debut in this game and they are slightly more dangerous as these are the variants that actually can reveal spikes out.

Diagonal chains of Bubbles are found in nearly every level of both episodes. Many of these chains appear over bottomless pits. This forces the player to use the Homing Attack. Unlike in Marble Garden Zone, Bubbles that appear in Sonic the Hedgehog 4 will not chase Sonic and remains stationary.

Sonic 4 Website Info

 * Bubbles is balloon fish type robot who returns back from the ruins of Angel Island. Due to Eggman's budget cuts, not all versiosn of Bubbles are spiked. However, watch out for the red ones!

Sonic Jump
The red variation of Bubbles appear at Jungle Zone in the 2012 remake of Sonic Jump. Like in Sonic the Hedgehog 4, Bubbles floats on the air and reveals spikes out quickly as the player can destroy it with Spin Jump with good timing.

Physical Appearance
Bubbles as Badnik is loosely based on real-life's pufferfish. Bubbles' blue body is smooth and spherical. On the front of its body has nozzle-shaped head with two big white eyes on each side. Back of the head can see a yellow-colored neckline. The back side of Bubbles has hole where goes few wires. Bubbles have 17 white spikes.

Since Sonic the Hedgehog 4, Bubbles appearance is slightly detailed, as the spike holes are purple and even now visible. Also Bubbles has only now 13 spikes. Bubbles neck hole is a slightly larger and under its body is the small rocket motor, which keeps Bubbles floating. Its backhole is also changed to seal air on each side of its body.

Abilities
Bubbles can hover in the air with small rocket motor, despite that it doesn't need that in its first appearance. Bubbles has all its spikes hidden inside of its body. Seemingly Bubbles can be harmless at first, but at a sudden moment it will reveal its spikes quickly and without any warning which can cause unexpected damage to the player.

Trivia

 * Performing a Homing Attack right as Sonic is below a Bubbles will cause him to stay in his uncurled form, allowing the player to quickly bounce through the rest of the chain of Bubbles. This avoids the brief cooldown between Homing Attacks.