Alex and Derrick are one time characters in the SMG4 series.
They are two characters who have so far only appeared together in the video "SM64: ṩṩἔᾗмὄḋᾗᾄʀ 6.64(100k special Qna Edition) (100k Special QNA Edition)". Derrick was telling a guy named Alex (his friend) that he looks like a hushpuppy, annoying him. He also tells him that he sometimes pretends to be a hushpuppy. Alex then replys saying "I'M ENJOYING A TREAT, DERRICK!!!" as he gets incredibly annoyed.