papyru

erm actually frisk is a toddler

toddlers dont kill giant flowers with tv heads

no, they don't
teens don't either-

lets just say frisk has no age???

not possible

so what age is frisk?

11.
its not any lower, frisk can read and write quite easily (mettatons quiz)
and they are referred to as follows:
"kiddo"(flowey & sans)
"my child"(toriel)
"a kid"(monster kid & alphys)
"human child"(undyne & asgore)
"child"(mettaton)
so they probably within range of 11-13
he cannot count past 4, so the youngest age seems appropriate
I rest my case

toddler

4

12

I think 9?

They do in Undertale