Seen a few combos from funny ideas out there and wanted to see what other people brainstorm.
Examples: shaco having a Jax in the box, Annie replacing Tibbers with volibear, and I just had one earlier where Thresh replaced his lantern with Tahm kench on a fishing pole.
No more missed lantern clicks anymore!!!
summons a 
(300 + (30*[number of minutes in the game]) stacks included) when using his passive.
Lee Sin + Taliyah = Toph
My job here is done.
Justice is blind
+
Instead of summoning soldiers he summons cows that you can't milk.
Ashe shoots a massive sej at people
Brad.
Brand and Bard.
Their Q spits a Brand Q that adds Blaze and stuns an enemy if it hits a minion, terrain or another champion.
Their W spawns a Shrine that if activated by an enemy, spawns a Pillar of Flame.
Their E spawns a Journey that if an enemy enters, it burns them for the duration, if an Ally does it cauterizes their wounds.
Ulti is a Tempered Pyroclasm, afterwards all enemies that were made invulnerable are hit by a bouncing Pyroclasm.
:^)
summons an immobile 
who channels his ulti instead of a pillar. Press E again to detonate.
+ 
quinn use Anivia for blind and for flying :D
+ Dunk of Justice
Prey seeker launches a 
at the enemy
+
Talon throws out a ring of Amumus that ult
turns into 
places little 
on the ground instead of turrets, which shoot his trademark poisoned darts.
ult spawns a friendly 
next to all ally champions.
summons little Nasus' and Renektons
