I don't think pacman frogs have any toxins. I think you can do that with most toads, but usually the fun part is followed by death. So I wouldn't suggest it.
Wrong genus for tripping, most psychotropics are Bufodae,
the toad lickers usually use bufo marinus( the cane toad) but it's toxin is very dangerous and consists mainly of bufotemine instead of DMT, side effects among toad trippers include vomiting, chest pain , heart attack, and death.
Bufo alvarius ( Sonoran river toad) is a different story, most of it's toxins are part of the DMT complex. It is seldom lethal, it's main side effects are nausea, and sweating.
Both can cause hallucinations though the sonoran's are supposed to be more intense and shorter lived. Both types of toad also have a transitory side effect in that while under the influences of the toxins the persons face tends to flush a purpleish color.
Here is an interesting link if you want to no more, http://www.tryptamines.com/