A skeleton of a flummel was seen in the flashback.
An island teleports into 200 years in the future. That would be surprising.
When Ed and Op found out what "extinct" means, they're determined to go back in time to save their species once and for all.
A couple of days in the snowy biome oughta cool Clarence down. Some wolves snarled and came close to him, that would be utterly intimidating.
If it was rated by the MPAA, it probably would be rated PG for some cartoon violence, rude humor, thematic elements and brief mild language.
If it were a videogame, it probably would be rated E for Everyone.