This is one of the few episodes of the Animated Series which I definitely recall watching as a child. I'll never forget seeing that scene where Bem separates into an upper and lower half in the lake, and those weird tentacle-like arms came out of his lower half to pickpocket Kirk and Spock. I distinctly recall being freaked out by that. It turned out I didn't remember much else about this episode, though.

Apart from the inevitable semi-omnipotent godlike incorporeal alien (which Gene Roddenberry threw into David Gerrold's script, because that's what Gene Roddenberry did to everyone's scripts), this is actually a nice episode. It has an enigmatically physically and psychologically different alien in Bem, and an emphasis on solving problems through diplomacy and negotiation rather than Kirk's usual repertoire of either phasering or making love to aliens.

Transcript

1
Captain's log, Stardate 7403.6. Commander Ari bn Bem of the newly contacted Pandronians is observing our explorations.
Bem: This guy has set beam down coordinates. {pointing thumbs at himself}
Kirk: Okay... not suspicious. Allons-y!
2
Caption: They land in a lake:
Caption: Bem's lower half uses Pickpocket. It's super effective!
Caption: Like Dr Seuss empty pants!!
3
Caption: Without phasers, they're captured:
Bem: You guys suck. Without violence, you are most ineffective.
Spock: He has a point, captain. There is diplomacy. We could do the sensible thing.
Kirk: We can't risk it! Let's do something reckless!
4
Entity: I am a semi-omnipotent incorporeal entity!
Kirk: Oh for crying out...
Entity: Leave my children alone! Leave this world.
Kirk: We come in peace. Can't we get along?
5
Bem: This guy misjudged you, Kirk. This guy failed. This guy must disassemble permanently as punishment. {pointing thumbs at himself}
Entity: What is punishment? Intelligent beings should learn from their mistakes. Look at Kirk here, always learning.
6
Spock: You speak wisdom. We will leave immediately.
Kirk: But... I haven't even taught the natives about love!