An elderly looking olive green tortoise-monster, Gerson wears archeologist attire, with a pointed beard, a large magnifying glass, and a tan pith helmet. His teeth are crooked and yellow and his shell is a dark brown color with a pale cream rim. He also seems to be unable to open his right eye.
When they have an offspring, the SOUL power of the parents flows into the child...
Causing the child to grow as the parents age.
But ASGORE doesn’t have a child.
So he’s been stuck at the same age...
And probably will be forever.
What if the child is a human...? What?
Nah. That wouldn’t work.
So if ASGORE’s your father, he’ll definitely outlive you.
[Asgore and Toriel]
Toriel was queen, and Asgore was the king.
It was tragic when she left.
Since everyone knew she was really the brains behind the throne...
But it was also just a teensy, teensy bit relieving, you know?
Those two were really insufferable together...
Nuzzling noses, bein' all cute n' cuddly in public...
Embarrassing their children...
They were so sweet it made me SICK.
Thank god those days are over!
She's really come a long way since she was a little urchin.
I used to be a hero myself, back in the old days.
Gerson, the Hammer of Justice.
When she was younger, Undyne would follow me around, to watch me beat up bad guys...
Sometimes she'd even try to help!
Though, most of the time the folks she attacked weren't bad guys.
It'd be the mailman or something like that.
Anyhoo, I appreciated it!
Wah ha ha ha!!!
Gerson's tarot card.
When attempting to name the Fallen Child "Gerson," the response becomes "Wah ha ha! Why not?" and allows the player to use the name.
According to Undyne, Gerson fought in The War of Humans and Monsters. If this is true, this places Gerson among the oldest characters in the game alongside Toriel and Asgore and also the oldest character biologically as Asgore and Toriel do not age.
As most monsters are based off animals from the real world, Gerson as a tortoise makes sense as the species is known to live up to around 150 years.
When selecting "Hero" in "Talk" on a Genocide Route, Gerson says that there is someone out there who will "strike you down." This may be a reference to Undyne the Undying, as in part of her introduction dialogue in the Genocide Route, she says that she "will strike you down!"