For Kled and Skaarl, could you try spoofing a Mario/Yoshi skin combo?
You got away with King Rammus, so why can't you get away with spoofing everybody's favorite Italian plumber? There's no need to carbon-copy Mario and Yoshi, but you could at least mimic the colors enough so that people get the reference.
And before anyone says "COPYRIGHT", I counter with "PARODY". Riot can't get sued for parody if the skin is an homage rather than a rip-off.
"Get out! Yer princess's in some otha castle!"