Magical Hybrids

In your opinion, what two creatures would make the most powerful hybrid?

Rhino-hippos.

RIP Rhinorambe

Real life? If by powerful you mean most likely to actively alter the world around it, Human-anything.

If you mean by just raw power, maybe a whale-anything.

Hippos and killer bees.

Peregrine falcons and swordfish

They dive at you at speeds approaching 300km/h with lance beaks.

Protagonist and Dragon.

Spider-men

Human and Silverback Gorilla

Human-ants

...

Never been that scared of italian pensioners user.

Hippo-whale would be fucking nightmare inducing

Play this game and find out.

Which reminds me I never could make the second DLC work. Welp.

human-human

Human Neanderthal

God-human

Dragon and Eldritch Horror
Breath weapon causes insanity (save for half damage).

Unless you mean real things...

Mantis Shrimp and Megalodon
Size of a bus, hits like a bus moving fast enough to break the sound barrier.

Or specifically extant creatures...

Manburg Virus and HIV
Basically, if you even look a man of color, you're going to die.

Or only living creatures whos life status isn't a controversy if it's a thing at all...

Fire ant and Bald Eagle
That bullshit comicbook thing about porportionate strength, a bite that ignites you with invisible flames, flight speed nearly reaching 100 mph, their ability to build nests that support hundreds of them, and whenever they attack that song from Team America (you know which one) blasts in your ears making it hard to communicate with your allies.

god-god

...

Quetzacoutl/Human

Flight/Brains+Opposable thumbs

I remember these, they were from some speculative what-if documentary, where they not?
These were bullshit, I remember them throwing prey and catching them on their swordbeaks midair without eyes while flying through jet-propulsion.
Bullshit.