This card is a EARTH equivalent of "Snowman Eater" since both monsters' effects activate when flipped up.
"Old Vindictive Magician" has the same ATK and DEF, and the same level, but the difference is the Attribute and the Type. They both share the same effects except that this card can destroy one of your own monsters, unlike "Old Vindictive Magician".
"Man-Eater Bug" is the larval or nymph form of "Nobleman-Eater Bug", which looks like a bigger, stronger man-eater bug with beetle-like wings. Also, "Nobleman-Eater Bug" has double the ATK and DEF of "Man-Eater Bug" and destroys 2 monsters on the field.