1. Traditional Fighters

Bubsy Bobcat

A purrsonal favorite of mine, quick and mobile rushdown fighter with a plethora of references to each of his (mediocre) games.

Origin: Bubsy Series

Delta Warriors

Mystic warriors of legend, they are three separate characters that attack the opponent based on what button is pressed.

Origin: Deltarune Chapter 1

PvZ Zombie

With a hoard of attacks built from special units that try to take your lawn, Browncoat is an undead undertaker that chews plants up.

Origin: Plants vs. Zombies series

The Mangle

The new face of playtime. Able to bring in 35 different allies with the selectable Prize Ball move to easily chomp out a win.

Origin: Five Nights at Freddy's series

Plague Knight

Hailing from the Order of No Quarter, Plague Knight can switch powders used in bombs to generate different (and explosive) results.

Origin: Shovel Knight

Risky Boots

Self-proclaimed queen of the seven seas, this lady-pirate can fire her pistol, able to reload ammo and use more at once for larger blasts.

Origin: Shantae (GBC)

Alphys

A shy dinosaur with an affinity for all things science. Charges her power to unleash a bin-breaking wallop of Nerd Rage.

Origin: UNDERTALE

Papyrus

The newest member of the royal guard, complete with fabled blue attacks. Select different Assists to use during the match!

Origin: UNDERTALE

Sans...?

Sans?
Is it Sans?
Do we know for sure?

Origin: UNDERTALE?

What's MUGEN?

What is this open-source fighting game called M.U.G.E.N?
https://en.wikipedia.org/wiki/M.U.G.E.N

You can download the stock game here:
http://network.mugenguild.com/justnopoint/mugen100.zip

(There should be all kinds of tutorials on the web of how to set it up, import characters, etc.)

YouTube Demonstration Channel:
https://www.youtube.com/channel/UCyHbaJSAmv28Ru9iwH4jSKQ

Disclaimer:

(All characters and music belong to their original owners. I do not claim ownership of any character used, as this is just a game engine in which people create/code characters to battle. No infringement of any kind is intended.)