Octopus

[tang daddy]

octopus are very strong and smart they can climb out of your tank and later climb back in the tank would have to be sealed and locked up as they can even force their way out. If you have any fish or inverts consider them food. If you have an overflow posibility for escape to your sump, Have you seen that video where the octopus climbs out of a sealed tank in a lab to go into another and steal fish then crawl back?

http://www.youtube.com/watch?v=_umYYoqaGl4

http://www.youtube.com/watch?v=rt17LLwtSC0

http://www.advancedaquarist.com/issu...003/invert.htm

you'd be safe with this type of tank
http://www.tonmo.com/forums/showthread.php?t=11134