[quote=@Birdboy]
Here is a basic Mock-up I made in my spare time. Everyone let me know what you think! I am open to edits. As is, I would say this is a pretty tough 1/2 Cr, I might end up taking a hit die from it.

[hider=Gallion]Gallion
Medium beast, unaligned
Armor Class 13
Hit Points 18 (4d8)
Speed 35 ft., fly 30 ft.
STR
12 (+1)

 
DEX
16 (+3)

 
CON
10 (+0)

 
INT
3 (-4)

 
WIS
10 (+0)

 
CHA
8 (-1)

Skills Athletics +3, Stealth +7
Senses darkvision 60 ft., passive Perception 10
Languages —
Challenge 1/2 (100 XP)
Keen Smell. The Gallion has advantage on Wisdom (Perception) checks that rely on smell.
Pounce. If the Gallion moves at least 20 ft. straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 13 Strength saving throw or be knocked prone. If the target is prone, the Gallion can make one bite attack against it as a bonus action.
Actions
Bite. Bite: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage.
Claws. Claw Attack: [+5] to hit, reach 5 ft., one target. Hit: 6 (1d6+3) slashing damage.[/hider]
[/quote]

The one thing I would like to point out is that a Beastmaster Ranger is supposed to have a creature of CR 1/4 or less, not 1/2. So this does seem a bit strong. That said, as somebody who has Ranger as their favorite class in the entire game, with BeastMaster as my favorite of the subclasses (at least it was prior to Fizban's Treasury of Dragons), I am well aware that Beastmaster Rangers are a TRASH tier class. They're fun to play, but they are extremely underpowered comparatively due to them needing more actions than they get to use in the action economy. Especially since Rangers often already want to have their Bonus Action for Hunter's Mark. So ultimately, I'm okay with giving them a buff like this.

I would personally make a few changes, though. 

Here's what I would probably recommend as a stat block: 

[hider=NOTE: None of the Feats are changed]
Medium beast, unaligned
Armor Class 13 (natural armor)
Hit Points 18 (4d8)
Speed 35 ft., fly 20 ft.
STR
12 (+1)
 
DEX
16 (+3)
 
CON
11 (+0)

INT
2 (-4)
 
WIS
10 (+0)
 
CHA
13 (+1)

Skills Acrobatics +5, Intimidation +3
Senses darkvision 60 ft., passive Perception 10
Languages —
Challenge 1/2 (100 XP)
Keen Smell. The Gallion has advantage on Wisdom (Perception) checks that rely on smell.
Pounce. If the Gallion moves at least 20 ft. straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 13 Strength saving throw or be knocked prone. If the target is prone, the Gallion can make one bite attack against it as a bonus action.
Actions
Bite. Bite: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) piercing damage.
Claws. Claw Attack: [+5] to hit, reach 5 ft., one target. Hit: 6 (1d6+3) slashing damage.[/hider]

But I will say that for the skills, for a Gallion, you could potentially swap Intimidation for Performance, I think, considering they generally like to be the center of attention. And it would be a bit more unique. But yeah, what do you think of this one? I figure it should have a bit more Charisma given its item description on Neopets. and if we want to go with Dexterity as its highest stat, then we should probably go with that one as its primary skill, but not going overboard with the actual number. I also reduced its Flight to 20 ft just because Flight is strong, but it can still use its Pounce from flight. I figured since it's a Medium creature, only Small creatures will ever be able to mount it or be carried, so it should be fine. 

[@XxFellsingxX] Although I will say that if you want to use Beastmaster, I would avoid using Revised Ranger. Because iirc, Revised Ranger does not get Extra Attack, which is usually very helpful for a Beastmaster, who is in desperate need of more actions. Plus, Revised Ranger is a long-since archived Ranger class set. I think it was replaced by the, imho better balanced, Optional Feats from Tasha's Cauldrom of Everything. Favored Foe replaces Favored Enemy, Deft Explorer replaces Natural Explorer, and Nature's Veil replaces Hide in Plain Sight. You could also look into Drakewarden, the new Ranger subclass from Fizban's Treasury of Dragons, which is essentially a Beastmaster but with a Drake that can be summoned.