The common Mexican tree frog (Smilisca baudinii) is a nocturnal species of tree frog whose native range extends from the Lower Rio Grande Valley of Texas south to northern Costa Rica. In Texas they are restricted to the counties of the Lower Rio Grande Valley and do no occur north of there.
There is a single record for this species in Bexar County that is almost certainly the result of a frog being transported in plants or equipment from the valley or elsewhere in their native range. This species does not naturally occur in Bexar county and no other specimens have been found.
The call of Mexican Treefrog is a rapid series of "honks". You can hear the honking of a pair of Mexican Treefrogs from Cameron County, Texas at the link below.
https://static.inaturalist.org/sounds/239090.mp3?1622362194