Three new indolic alkaloids with a tricyclic N-methyltryptamine (physostigmine-type) structure and isoprene-derived side chains were isolated from skin extracts of the Australian frog Pseudophryne coriacea. Their structures were elucidated using gas chromatographic-mass spectrometry (GC-MS), chemical-ionization mass spectrometry (CI-MS), nuclear magnetic resonance (¹H, ¹³C, 2D COSY), and chemical interconversions. The major components included pseudophrynamine A (a dimeric ester, 2) and pseudophrynaminol (1), with a minor methyl ester (3) also identified. Stereochemical assignments (e.g., E configuration for allylic moieties) were confirmed via NMR comparisons and 2D NOE experiments. Methoxide cleavage of 2 yielded 1 and 3, verifying their structural relationships. These new alkaloids feature isoprenoid units linked to a tricyclic N-methyltryptamine backbone, and the names pseudophrynamine A and pseudophrynaminol are proposed for the previously unreported compounds.