|Affiliations|| Ben Tennyson|
|Relatives||Donovan GrandSmith (Grandfather)|
|Voice Actor||Kath Soucie|
|First Appearance||They Lurk Below|
Edwin GrandSmith is the grandson of Donovan GrandSmith, a wealthy resort chain CEO. Tending to be slightly arrogant, off-putting and selfish, Edwin was in the underwater resort when it was attacked by some robotic jellyfish/octopus-like aliens, that almost seemed like machines. After seeing Ben Tennyson disappear and "suprisingly helpful aliens" appear, he began to guess Ben's secret. After being trapped with Ben and his cousin Gwen in a tunnel that was rapidly filling with water, Edwin finally guessed Ben's identity and revealed this. Edwin then traveled with Ben into a chamber with the Undersea Manta Ray, saw Ben transform into Upgrade and escaped via the upgraded sub.
- They Lurk Below (first appearance)
- According to Matt Wayne, there are no plans for Edwin to return, but it's possible he will.