Lion

Lion is a magical pink lion befriended by Steven in "Steven's Lion" who occasionally comes to Steven's rescue. It is revealed in "Lion 3: Straight to Video" that Lion has some form of connection with Rose Quartz. This connection is explored further in the episode "Rose's Scabbard". It is later revealed in "Lars' Head" that Lion was once a normal lion that was revived, turned pink, and bestowed magical abilities through Rose Quartz's healing powers. Lion's mane contains a pocket dimension that houses many of Rose's belongings and, until the episode of the same name, Bismuth.

Appearance
Lion has round ears, pink fur, black eyes, a soft light pink star-shaped mane, and a dark brownish-magenta heart-shaped nose. When Lion uses his magical abilities, his eyes and mane emit a white glow. There is a tuft of soft pink fur at the end of his thin tail.

Personality
Lion is an enigmatic creature whose sentience and sapience is somewhat questionable. However, he seems to act like a typical house cat, doing things like chasing butterflies in "Rose's Scabbard" and snapping at the dragonfly-like lights created by Sardonyx in "Cry for Help". Much like a normal animal, he rarely changes his expression and for the most part, he is quiet and docile. Though he is considered a "pet" for Steven, Lion looks after himself and often sees to his activities. While Lion does not seem to acknowledge Steven most of the time, he does appear to understand Steven to a certain extent, responding whenever Steven needs him in mysterious ways. "Lion 2: The Movie" shows this understanding when he takes him and Connie to Rose's Secret Armory. Steven remarks how Lion is not "trained very well", and in "Lion 3: Straight to Video", Lion nearly smothers Steven's face to show him the dimension in his mane when Steven said he wanted to know more about his mother.

History
Little is known about Lion's history before meeting Steven and the Crystal Gems other than the fact that he had affiliations with Rose Quartz prior to Steven's birth. When Steven and the rest of the Crystal Gems are searching for the Desert Glass in "Steven's Lion", Lion is found by Steven in the middle of the desert. It can be assumed that this is where Lion lived before being found by the Crystal Gems. Steven is afraid of Lion at first but comes around to him quickly after realizing that he is not a threat. This leads to Lion following Steven back to the Temple and eventually joining the Crystal Gems.

While Lion's exact origins are unknown, Rose is shown talking to Jamie (Buddy Buddwick) in "Buddy's Book" many years ago with several regular earth lions surrounding her, in a similar desert to the one Lion was found in. This could be where her magical pink lion came from. However, none of the Crystal Gems knew about Lion before being introduced to him by Steven, implying that Rose never shared Lion's existence with Garnet, Amethyst, or Pearl.

In "Lars' Head", it is heavily implied that Lion was previously an ordinary Earth lion that died, before being resurrected by Rose Quartz. Due to the resurrection, Lion gained his unusual appearance and unique abilities.

Abilities

 * Concussive Roar: Lion has a loud, powerful roar that sends pink rings to destroy/knock down structures. Examples include knocking down multiple sand constructs in "Steven's Lion", pushing the remains of the Gem Warship in "Jail Break", and trying to defeat Lapis' water clone of Steven in "Ocean Gem". In "Crack the Whip", his roar sends the Snow Monster flying.
 * Dimensiokinesis: Lion can manipulate dimensions with relative ease.
 * Portal Creation and Manipulation: Lion's roar can also open up pink portals, connecting two non-adjacent areas. "Lion 2: The Movie" first shows this when he takes Steven and Connie to Rose's Secret Armory, and additionally when going to the Gem Communication Hub in "Cry for Help". He also uses this ability to bring Connie and Steven to the Maheswaran residence in "Nightmare Hospital" and when Lion, with Connie on his back, rescue Steven in "Ocean Gem". Lion also uses this power to find and bring Steven to Pearl in "Rose's Scabbard". Lion can create portals that help him cover enormous distances as shown in "It Could've Been Great" when he creates a portal from Earth to the Moon in mere seconds. This does leave him fatigued afterward, possibly due to carrying Garnet, Amethyst, and Pearl on his back and Steven and Peridot in his mane while traversing the portal.
 * Acceleration Portal: Once inside his portal, Lion can create multiple portals that cause him to accelerate with each pass on an individual portal. This trick is likely done to increase speed and distance traveled, As seen in the episode "It Could've Been Great".
 * Pocket Dimension: Like Pearl, Lion has a pocket dimension that is currently only accessible through his mane as well as Lars' hair after his resurrection. This dimension is a vast pink savannah that now includes two grassy hills, one with an acacia tree and another with a tree resembling an oak. As shown in "Lars' Head," Steven (and presumably others) can travel through one entrance and exit through the other.
 * Dimensional Storage: Rose stored some of her most cherished and important belongings inside of Lion's mane for safe keeping.  These include a variety of items, such as her sword, a photo, and videotape of her and Greg, a treasure chest, the Mr. Universe Shirt Greg gave her when they first met, a tattered flag with Rose's symbol, and Bismuth's gem. It also contains some of Steven's belongings such as his bike, helmet, some magic trick paraphernalia, soda, and probably much more. Thus far, Steven is the only one who can directly access Lion's dimension, as we see when Pearl touched Lion's mane with little success.
 * Supernatural Stamina: Lion has incredible stamina, as shown in "Ocean Gem" where Lion kept pace with Greg's Van for an entire day while carrying Steven and Connie. He also demonstrates the capability to leap far distances. However, his stamina does have limits, as in "Cry for Help" when after carrying all three Crystal Gems with Steven in his pocket dimension, he shows signs of fatigue. "It Could've Been Great" further shows this limitation since the strain Lion feels is directly proportional to the distance traveled;  making a portal from the Earth to the moon was enough to make him collapse and breathe heavily.
 * Water-Walking: Lion can walk on water, as seen in "Lion 2: The Movie" when he takes Steven and Connie to Rose's Secret Armory. He shares this ability with lapis Lazuli, Opal, and Pearl.