Rover (TLKOE) and Izuku Midoriya

Izuku fell on his stomach with a grunt, he looked up to find himself in some arena with nothing but the metal floor and a large gate. He saw Tomura, Himiko, and Dabi standing on the balcony.

"You're in a terrible situation. Aren't you, Izuku?" Tomura taunted.

Izuku scowled up at the white haired boy and tried to leap for him, but crashed into a window and slid down to the floor. This earned a chuckle from the trio of villains.

"You'll have to give that window a few powerful punches, its really durable." Dabi informed, smirking.

"But you'll have to focus on something more important first." Tomura laughed before yelling, "Open the gate!"

The large metal gate slowly slid up as Izuku heard something snarling from within the shadows. A large, blue canine-like monster emerged. It gazed at Izuku for a few seconds before growling up at Tomura, who simply gave the blue monster his middle finger.

"Izuku meet Rover, Rover meet Izuku." Himiko said cheerfully.

"This foul beast is going to make a meal of you and the One for All will cease to exist!" Tomura granted, fully confident that his plan would work as Rover's speed and strength would impress those with powerful quirks. He couldn't wait to see All For One be proud of him for his accomplishments.

Rover roared and crouched in position to lung at the white haired menace, before yelping when one of the guards zapped his side with an electric staff. This was made to force Rover to bare his fangs at Izuku instead. Rover did not like this and snarled at the guard, before pouncing on him and grabbing his head with his jaws. The guard screamed, a high-pitch scream that a little girl would make, as he was shaken from side to side and flung into the window where Tomura stood behind. Tomura jumped at this, before regaining his composure and glaring angrily at the stupid beast for humiliating him. He was so gonna disintegrate that thing after it ate Izuku.

Izuku ran to check on the guard, relieved to find that he was just unconscious. Only to see Rover charging toward him, drooling with his tongue out on the side. Izuku jumped to the glass window, then jumped again when Rover leaped for him. Tomura watched impatiently as the blue blur chased after the green blur.

Eventually, Rover stopped and lunged in another direction. Izuku's eyes widen as he realized what the blue monster planning, but he was too late as Rover closed his fangs on Izuku's green hood and flung him down into the floor. Dazed, Izuku didn't react fast enough as Rover jumped on top of him and pinned him down.

"Finally!" Tomura cheered, now Izuku will die!

Rover continued to snarl down at the green haired boy, who winced as droplets of drool fell on to his face. Izuku was about to give the monster a powerful punch.

SLURP!

He felt a large tongue that covered his whole face drag from his chin to his forehead. When Rover flicked his tongue off, he panted down adoringly at the teen.

Izuku blinked at this as he thought Rover was a savage animal but apparently that's not the case. Rover lowered his head and continued to lick his face excitedly, forcing Izuku to scrunch his face up.

"Hey, cut it out! That tickles!" Izuku sputtered as he tried to move his head away from the slobbery affection but Rover moved closer now licking at the side of the green haired teen's face. Izuku smiled as the slobbery tongue rolled his cheek up and forced one eye to close. Eventually Rover ceased his affection, for the moment and got off the child. Smiling goofily, Izuku got off and wipe his face with his costume sleeve.

"WHAT THE F--- IS THIS?!"

Both Izuku and Rover looked up to see an enraged, and Izuku meant ENRAGED, Tomura, who's hand mask had fallen off, revealing his clenched teeth and raging eyes.

"You're suppose to kill him, you stupid mutt!"

Rover growled and roared at the villain, placing himself between the villain and his new green friend.

The monster dog was about to leap again when All Might smashed through the wall. "I AM HERE!"

"Crap!" Dabi deadpanned as he and Himiko, with a cheerful smile, restrained Tomura as they went through the portal to avoid confrontation with All Might.

All Might was baffled by the sight of Izuku with his arm wrapped around big, blue monster that panted and drooled on the the floor. Izuku was giving his mentor a pleading look.

"Can I keep him?"