Phyllobates terribilis - yellow poison dart frog
-No it's not aggresive, only during breeding season where males tends to fight for a female. This frog carries batrachotoxins that cause irreversible muscle contractions leading to heart failure. A touch from this frog could prove lethal, since minute pores pour out toxins that can enter our skin pores. But, as study shows that although in captive conditons they retain their toxins, most captive bred ones has zero amounts of toxin (because study shows that toxins are created during digestion of native insects and bugs compared to a feeder roach or mealworm, which does not aquire compunds to make toxin necessary for the frog.) Indian hunters tip their darts (hence the name) w/ these frogs, holding them in foot w/ a leaf barrier. Then when they hunt w/ their blow dart and striked, say for example a bird, they
lick the part of the carcass to locate the spread of poison and cut it away. Why the indians can't ingest the toxins is unknown.
reference:
National Geographic Magazine VoL. 187, No.5 May 1995