This was accidentally said in real life at school by a guy called Oliver. He meant to say Heck Yeah, but ended up with Heck Yeck. Despite popular belief, this was first said by Oliver, and not by his internet friend wHO IS TAKING CREDIT FOR IT. I can tell you that, because I witnessed the glorious event. It was first posted on discord, and has spread between servers with both myself and Oliver using it. There is also apparently something going around Tumblr about heck yeck, but we're talking about this newer, more popular generation of yecks. Feel free to use this phrase, its not copyrighted (yet).

meme saying catchphrase made up word