Dr. Craven was part of the scientific team sent to Panama to investigate reports of a giant creature coming ashore there. While there, Mendel delivered a video tape containing information on the creature to Elsie Chapman and met Niko Tatopoulos. Craven played a very minor if nonexistent role in the subsequent efforts to destroy the creature, later dubbed Godzilla by the media.
Following Godzilla's defeat at the hands of the military, Craven was working alongside Elsie Chapman, only for the military to seize their equipment. Mendel and Elsie decided to join Niko Tatopoulos' scientific team, H.E.A.T., to study the various gigantic mutations appearing around the world. Mendel also brought along his invention, N.I.G.E.L., to assist with H.E.A.T.'s efforts. From then on, Mendel traveled with H.E.A.T. and the new Godzilla around the globe, discovering new mutations and alien threats. Mendel affirmed his position as a coward with a sense of duty, and was cemented as the leader of H.E.A.T. whenever Nick wasn't present.
In an alternate future where the world was overrun with creatures called D.R.A.G.M.A.s that wiped out all of Earth's mutations and most of humanity, Mendel was one of the leaders of mankind's last resistance against the creatures, along with Anthony Hicks. The rest of H.E.A.T. was pulled into this future and met the future Mendel, who told them about how they all disappeared one day only to resurface now. H.E.A.T. managed to return to the past and with Godzilla's help destroyed all of the immature D.R.A.G.M.A.s, preventing the hellish future from ever coming to be.
- Mendel has dirty-blonde hair in the animated series, even though in the original his hair is black.
- Mendel has numerous allergies, which becomes a running joke in both GODZILLA and Godzilla: The Series.
- He is specifically allergic to: Several varieties of trees and shrubs, most grasses, a couple dozen animals, 25 or so foods, rubber and rubber products.
- Mendel is the creator of H.E.A.T.'s research robot N.I.G.E.L.
- Mendel Craven and Anthony Hicks are the only characters in Godzilla: The Series to be voiced by the same actors who played them in GODZILLA.
- Mendel took bagpipe lessons in high school.
- Mendel is skilled at Origami.