Despite his duty, Senior is actually rather careless, as he often falls asleep during his job. As a result, his museum can become an easy target for thieves. Senior also seems to be scared of insects, as he tends to ask someone else to do anything important that involves those creatures. He's also scared of frogs and mice (even including the tree friend-looking ones).
Sometimes, he wants to kidnap Cro-Marmot or any other tree friends that are part of the past times, just to fulfill his museum's collection. He isn't as dumb as Lumpy, but once he sees someone that looks like a prehistoric or historical figure (even if he/she is merely dressed up as one), he might go crazy and chase after him/her.
- In Simpsons episodes, he takes place of Dr. Marvin Monroe.